The way I handled him today was simple: I didn't lose my cool. Zoom's always said he likes to get people angry and to waste their time, so when he tried to claim I was stolen valor, we let him make his case. At individual segments I'd explain why he was wrong, and he'd stick to how he was right, even when I provided the actual rules and regulations to him concerning things such as the time difference between men and women on the 3-mile run on the PFT (he said it was 30 seconds, it's actually 3 minutes and I told him that). He'd start to get angry, he'd start to yell, he'd start to grandstand and my only response was, "Keep playing Zoom's video". The only thing he was able to latch on to was me saying "AR 160", which I corrected to "AR 670-1". He admitted he heard me correct myself, but he wanted to make it seem like what I had meant was different. Finally, I had proven him wrong on multiple things, many of which are easily Google'd concerning Marine life and all he could do was repeatedly say, "I don't believe you" like a broken record.
That's the key to handling it. You don't lose your cool, the only people who listen to him are the trolls who follow him. Zoom's a sociopath and nothing more.