"I felt like I had failed him, or could have done more." -- This sounds like the actor died as a result of a wrong choice, not from a freak car accident.
He did a great job in Odd Thomas. That movie got too little attention. I say that not even knowing about the book. Interesting enough, one person who watched it with me yawning or nearly falling asleep during most of it was at edge of couch during last scenes. They totally flipped its style on audience.
I'll remember him that way in a movie where he played a great character dedicated to entertaining and protecting the rest. :)