To quote Dean Wormer:
Fat, drunk and stupid is no way to go through life son.
Not surprised that he fell off the wagon (provided he was ever back on it to begin with, since he's lied about it in the past). He has said on numerous occasions, including in "Too Fat Too Fish", that when he gets bored, he gets into trouble. The two-week break definitely gave him a lot of downtime (As the saying goes, idle hands is the Devil's workshop.), and I'm sure going out to Vegas right at the beginning of it really was a smart idea (Even if he was on the wagon in Vegas, there's too much temptation for someone with addictions and demons like he has.). At least last year during this break, he had the USO trip to Afghanistan to keep him occupied (and somewhat keep him away from trouble) for the bulk of the break.
The folks on the Stern Fan Network (It took this happening to get me to post on there for the first time in a few years.) were laughing about the fact he was driving a Nissan. That car is more than likely the rental car his insurance company is paying for while his Mercedes is being repaired after getting damaged several weeks back (The story behind it getting damaged is definitely being questioned after this incident.).
Perhaps this is the incident that actually forces him to get his act together, as much like with his 1997 cocaine conviction in California, he could be sent to court-ordered rehab. It might take him losing out on $100,000+ in gig money, and perhaps even being suspended from the Howard Stern Show (I'm sure that by Monday morning, Howard will have already ripped Baby Gorilla a new one.) for him the realize he needs to do things right to get clean. The way he chose to get clean was destined to fail (I'm sure Dr. Drew is feeling smug about being right there.....), especially since Artie never has really had to pay for the consequences of his actions in the past. He was fired from Mad TV
because of the cocaine incident, got out of his rehab program back home in NJ
by paying off the guy running the place so he could do "Dirty Work", which led to his career getting back on track. He never has had to fully pay the piper.