Not quite the same as the OP but I've had moments of kindness in MMO's in the past that showed me that the internet is not all trolls and swearing.
Playing FF11 first, had just started, having trouble killing things was getting more and more frustrated with the game when a higher level player saw the trouble I was having and messaged me asking if I was ok, I said no I was having trouble getting the hang of it
The next 3 hours he spent with me, explaining the jobs, mechanics, how to do x,y and z and was incredibly patient. When I had to leave he said "one last thing before you go" and bought me a set of armor from the auction house then added me to his friends list
Haven't played that game in over 8 years but that still sticks in my mind, he was max level, he could have been doing anything in the world but he took the moment to spend time with a guy who had just started
The other was in WoW, during Wrath of the Lich King, I was in howling fjord on my Draenei Shaman to the south doing the quests for the pirates, saw a blood elf had pulled an elite and a few other mobs and was having real trouble, I headed over, helped him clear everything out, did a /bow emote since players can't communicate cross-faction and went on my way
About half a minute later I got a whisper from a guy explaining he was the father of the child playing the blood elf, wanted to thank me for taking the moment to help him out, he had been having a bad night with the game and many other players so to show him not everyone was bad meant a lot and wished me a pleasant evening, made me smile that such a simple thing could mean a lot to someone