Basically, before the incident, Angry_Squid was on, not on a team though. I started chatting to the other players and Angry_Squid starts correcting me which gets very annoying quickly. I ask him to stop and he starts, well, acting rude. Then, he decides to join my team because he knows that i'm just hiding from the other team because i'm the only one. He starts to break my bunker which causes me to die. Then why I try to rebuild it he blocks up all the water as seen in the video. When I build up elsewhere he follows me and disallows me to pillar up and place blocks. Then the last time he interferes he actually kills himself just to block up my water... but fails. After the round is over he continues to be rude to me when I did hardly anything, making me seem rude when all I wanted was for him to leave me alone. There is also a video by the way, for the greifing portion.
Video - https://youtu.be/fFjBlgeipq0