The guy is probably likely to present well enough if the interview isn't too demanding and he will get the job.
He will be on a probationary period and HR will probably fail to fire him within that period and if a UK company, they're stuck with him.
What they then have to do is follow the procedures and document every failing until they are bullet proof on justification to sack him. They may even keep him on when they make others redundant just to be sure he doesn't profit financially from a redundancy.
Seen it done.
At least in the US they can usually can him immediately they discover he is defective.
The correct procedure is to interview with particular attention to his CV claims, explore his references and then not give him the job.
Yeah, that's gonna happen?
In "The Apprentice" (UK version with Sir Alan Sugar of Amstrad fame) in last years contest one contestant said he had been two years at University but in the interviews the interviewer found him out... he'd been for just four months.
Guess what, he won the competition.
(
The reason you have to worry is that he will be blocking jobs others deserve and because Management and HR are sloppy or have strange ideas about acceptable behaviour.
More important, how widespread is it?
My last company they hired some guy (after I'd left) who had impeccable references and CV but HR fell down on the job and they only discovered, during his first week, as it happens, that he was an illegal immigrant (who had nicked the identity and CV from an online recruitment site) when the police contacted when they caught him in a disused warehouse.
JMW