Gang Burrito spawn in Fort zancudo?

I was playing with my friend, doing MC missions together, we were flying around in B11s and landed down in Fort zancudo because he wanted to change the livery, he said that the jeeps were mad at him, then I landed down too and realised that they weren't jeeps, but gang burritos with normal civilians driving them? I don't have a screenshot because I didn't think about reddit in the moment, this happened today, but has anyone had it happen to them before, is it a glitch? Or some weird event?