There has been posts of another angle, and after seeing that I'm less sure. Part of it still looks like his hand clips through a mic, but if you go through them slowly, side by side, it does show a bunch of boom mics and you can follow how they could intersect to give the effect.

Either way it still looks weird, since Biden walks right up basically sitting on the mics, but only says one thing then leaves. Something is fishy even if it isn't video manipulation.