Is my friend a douchebag?

[WLVRYN]

I recently got back from a trip and had a fairly nasty argument with a good friend, and I want to see OOT's opinion as to whether he's a douchebag or not. Here's the story:

Before I left on my trip, my friend offered me a ride to the airport (and to pick me up when I get back) in exchange for me taking him (and picking him up) when he heads out of town in two weeks. About a mile from the airport, he's changing a CD and doesnt see the car in front of him stop. He rearends the car going about 20 MPH. We get out and everyone's OK, but both cars are fairly damaged. At this point, I'm running a little late and didnt want to miss my flight (to a bachelor party), so I tell my friend that I'm just going to hitch a ride from the bus at the car rental place that happened to be right there and I'll catch up with him when I get back at the end of the weekend. Obviously I feel pretty bad for the guy (and tell him so), but there's not much I can do at this point, so I figure there's no harm in getting to my flight.

When he picks me up on Sunday night, he tells me that the estimate to fix the car is over $1,500. His insurance covers this, but since the accident was his fault, he has to pay the $500 deductible. At this point, he asks me to pay for half the deductible since he wouldnt have gotten into the accident if he werent driving me to the airport. I tell him to go to hell, that its not my fault he wasnt looking, and that we had both agreed to take each other to the airport (his idea by the way), so its not like he went out of his way to help me out. We both have jobs for decent money, so I dont think the money is really the issue. He's pretty adamant that I should pay half, and I'm pretty sure that he probably wont want to be friends anymore if I dont. We've been friends since junior high (he stood up in my wedding) and I've never seen him like this. I'd hate to lose a friend over something as stupid as this, but I dont think its reasonable to expect me to pay for his crummy driving.

So I ask OOT, is my friend a douchebag?