I had then confronted Tenant B  and he makes excuses and lies about the situation.

Too much positivity can imply that no one is willing to confront the real problems and challenges they're facing.

@Sami Gren I am skeptical of authority intervention--you do not want to escalate to confrontation.

Although it was clear there was a physical confrontation, and the size difference and boyfriends demeanor tells me what was going on, I am assuming my logical conclusion is not legally valid.

If you wanted to give him a heads up that this will be happening on a certain day, you may avoid a confrontation. 

Confront the landlord (it seems he does not realize she has security cameras) and risk him getting angry?  

@Matt Fischer I'm not sure why people are soooo afraid to confront a problem head on.

The electrician we hired also took significantly longer than he was supposed to, but when we confronted him about it, his reasoning was because the PM wasn’t completing work on their end that needed to be done for him to do his work.

When I confronted this question they only mentioned it's normal in our market.

I confronted him and told him to get the f out of my property and never come back.