Not a yank, surely .. ?
Now, a bit of low-brow analysis here would lead me to suspect that this person is in fact an Englishman abroad. It's not often that the transatlantic types would off up the rather short "you cunt" in such a decidedly British manner.
Although, perhaps said suspected-Yank is a die-hard Guy Ritchie fan - but, realistically, what are the odds of that ?
That said, Jason Statham appears to have upped-sticks and moved over - perhaps he was just visiting some IT corp as research for his next flick ("They picked the wrong guy to downsize and outsource this time - and he's going to take 'terminal' literally" etc..) and saw an open console ?
"Crawl back under the rock you live under" does seem a bit wordy. Though if I'd been having a crack at Kelly Brook for a few years, I wouldn't particularly care about my grammar either...