You know, if it's legally untenable for YouTube to escrow the money, just change the policy to be "Videos that are in dispute are ineligible for ad revenue until the dispute is settled."
This isn't ideal, but it would completely cut the legs off of anyone attempting to steal ad revenue without proving infringement. It'd take out a good chunk of what's going on, and make it easier to focus on the other abuses -- the ones where videos are taken down just because the company doesn't appreciate Fair Use, the ones where jerks are just harassing creators, and the robotic claims.
Also, the robo-flagging issue needs to get fixed. First, set up categories of Almost Certainly Fair Use, Maybe Fair Use, and Probably Not Fair Use.
When you post a video, you need to specify if you're using material you don't own, and what the general categories of your defense are: It's a review, it's commenting on or criticizing the material, it's educational, it's a parody, it's transformative, etc. This should make it easier to see what's going on, and to direct it to the right staff at YouTube.
Secondly, YouTube needs to set a couple thresholds for the amount of copyrighted material used from a single source. I suggest 40% is the high threshold (under half a song/episode/movie, with generous wiggle room so you can't just split it in half and post two vids), and the low threshold is based on the type of material, say 25% of a song (or under 1 minute 1 second), 15% of an episode (or under 4 minutes, if it's a 20-30 minute episode), 5% of a movie (or under 5 minutes, if it's a roughly 2-hour movie).
Game footage is exempt from these thresholds due to two criteria: There's a much larger amount of content in a game than in a movie (generally), and the reality of an interactive medium means showing footage doesn't inherently reduce the game market.
If your video passes the high threshold, you've posted something like half a song/episode/movie or more, which means your video hits the Probably Not Fair Use pile. I could see one category that avoids this: If a source has both audio and video, but your video uses only one of them (pairs footage with new audio or audio with new footage), it's more likely fair use even if it's longer, so stick it in Maybe Fair Use. (The robots need to be able to recognize basic changes such as just altering the audio a little, and be able to catch songs played against a static background image.)
If you're under the low threshold, you've posted a tiny amount of the material, and are Almost Certainly Fair Use (two-second videos should not be auto-flagged! honestly). Fewer problems for you. If you're between the two, you're in Maybe Fair Use.
Some categories may have different likelihoods of ending up in the piles. For example, marking your video as Education might have it end up in Maybe Fair Use even if you've used 100% of the material. I'm not sure which categories might warrant special treatment like that.
This puts incoming videos that rely on Fair Use in three piles. Make a group of YouTube staff members responsible for reviewing videos to determine their likely status. The group that reviews Almost Certainly Fair Use can just have a reasonable layman's understanding of Fair Use; they're just trying to look for the "hey, that's totally not kosher, dude" videos and move them to the Maybe Fair Use pile (or Probably Not Fair Use, if it's pretty obvious there's a problem). Anything they think is probably fine goes into the "we gave it a once-over" category and no action is taken unless someone human actually makes a claim against it later on.
The Almost Certainly Fair Use group is also there to confirm that the categories the poster indicated are what is actually happening in the video. Is it really a review? Really commentary or criticism? Really educational? Really a parody? But mostly they're there to ensure that reviews, commentary and criticism, and education are quickly vetted so they don't have to worry about robo-flags or trouble unless someone who actually owns the material comes along to make a claim.
The group that reviews Maybe Fair Use should probably be lawyers who specialize in Fair Use. They just push the videos in one direction or the other: Yeah, it's fine (Almost Certainly Fair Use) or Dude, that's not cool (Probably Not Fair Use). Point is that a human is reviewing it directly, in context, not relying on robots.
The Maybe Fair Use group turns a closer eye on parodies, fanvids, machinima, cosplay, and in general things that are less obviously Fair Use. They're trying to figure out if YouTube should spend more time vetting these videos or not. (Note that if a video gets bumped between Almost Certainly Fair Use and Maybe Fair Use a couple times, it warrants a closer look by an actual lawyer.)
The group that reviews Probably Not Fair Use has to be lawyers who specialize in Fair Use. This is the category where the video probably gets action taken against it -- unless the lawyer goes "Oh, yeah, that's following the law" and bumps it straight to "no problem" (it doesn't get reviewed by the other groups, it's just fine at that point).
If the lawyer thinks it's not Fair Use, or that it's strongly questionable, then the process starts. Firstly, YouTube notifies the video's creator that their video is in iffy status, and gives them a short time (say 3 business days) to either change the video, or provide a defense for their usage. If the video is taken down, the creator's account gets a tally: If an account posts and then takes down non-fair-use videos a couple times, they can be assumed to just not understand the boundaries, but if they do it more than say 4 times, they get moved to a watch list for a while, where their robo-flagged vids have to get reviewed by YouTube's lawyer before they are eligible for public status.
However, if the video doesn't get taken down -- if the creator provides a defense -- then YouTube notifies the owners of the content to come look at the video themselves (through a non-monetized link). This method should also remind them of how Fair Use works, and that they don't have to like what the video is doing to their material, but if they do think infringement has taken place, they can file a claim like normal. If they choose not to file a claim, the video's fine.
I think a system like this would reduce the burden of the ContentID system on reviewers, critics, and educators, make it easier to avoid trouble if you're into more transformative works, and push the bulk of the penalties onto people who are using a larger portion of the material or using it in less defensible ways. Plus, it would leave the question of claims to the companies who actually own the stuff, not have YouTube make it on their behalf -- this would stop the cases where YouTube's system penalizes videos that the content owners were perfectly fine with.
Also: There should be a "Keep Circulating the Tapes" category for material that is not in the ContentID system but is actually fully reposted material where the original owners can't be located or the like. This applies for stuff like old commercials (who'd've predicted that being able to watch a commercial or PSA from the 90's would be valued today?), shows and movies and songs that otherwise would be gone from our collective history, and potentially behind-the-scenes footage or dailies, etc. Until such time as a legitimate claim from the original company comes up, these repostings can be left alone because they are helping preserve material that might not even have an owner anymore. Recorded TV broadcasts that never made it to DVD, for example.
Anyway. Changes need to happen, and the community brainstorming the changes is at least helpful in looking at the pros and cons. I've got a video up on YouTube about my take on things (not detailed solutions, but some talking points and a lot of irritation), which is called "Sharks, Robo-Sharks, Crabs, and Leeches: Fair Use Under Attack." Those terms are for the types of people filing false claims, which the video explains, because I think we need some anchors for these concepts so it's easier to discuss them.