Shizuo Heiwajima gets shot on which episode I can't find that clip I know when the Yellow Scarves gets overtaken by the Leader of Blue Squares and one of the Yellow Scarves gang member shots Shizuo and blames Masaomi for that but i cant find that episode.
The scene is from episode 22. It begins around 21:20 and ends at about 21:55, at least on the Japanese bluray. 

You probably haven't been able to find it on YouTube due to the content ID system; there is seemingly some background music or something during that scene that causes it to get instantly blocked.