Officers are very very rarely giving you a chance to explain your way out of a situation. They knew he was drunk the moment they smelled the alcohol in his car. The first question he asked, and any officer would ask in that situation is "How much have you had to drink tonight?" Pay attention closely. They don't ever ask, "did you have anything to drink" because the obvious answer to even an idiot is to say "no", instead they ask a question that puts the suspect in the frame of mind- "they already know I've been drinking so I'll try and say it was just one drink or two drinks" thinking that just one or two drinks means you can walk away. In reality, it doesn't matter how many drinks you say you've had, you just admitted to drinking. The officer continues asking him questions, not to let him go, they know they're not letting him go the minute they look up his rap sheet and find out he's violating parole. They ask the questions to get the guy comfortable and take his guard down. The drawn out interrogation is a very smart control tactic, get the guy to not be defensive and convince him he's only going to the station for the breathalyzer test. Unfortunately the dude had been to jail before and panicked the second they tried to cuff him.

You should never talk to police. They aren't there to give you a chance to explain things. They are giving you rope to hang yourself.

Obviously this isn't true of all police, I've seen officers bend over backwards to help idiots that probably should have spent a night in jail, but in general...don't talk to police.