To me it's how the sentence is delivered and in what tone/context.
So - 'You always lose the fucking keys FFS' yelled at you as the other person is trying to leave the house for an appt say, is out of order for sure.
But - 'You always lose the fucking keys you fucking (Insert name calling)' is verbal abuse in my book.
Say he called her a 'f**kin C@nt.' That's a personal attack, abuse.
By displaying frustration by saying something like the first sentence, is less so to me. Not that I'd accept either, he'd get a verbal slap up side his head, delivered in the nicest possible way. 
I think that if it was a regular thing, daily, etc, then clearly he has issues with taking responsibility for himself. If he knows he'll need to keys, make sure they are there before the time to leave comes.
If not, if he continues to 'pick a fight' then there's more to it surely?
Does any of that make sense? I'm knackered! 