Who is in the wrong here?

So my channel got terminated for copyright, and yes, I did use someone's else's videos, but their channel description basically said "If you use my video give credits" But he still striked me, even though that is basically permission? I didn't do this just because I was too lazy to make content, it was a massive trend in my niche where ppl were using clips from his videos and making a meme with them, and getting massive views, and he didn't strike anyone until after around a couple weeks had passed. I understand why my channel got terminated if I was in the wrong here, but idk if I'm right or wrong.