You have to back the guy's decision in these circumstances. If the fire had got rapidly worse and he hadn't called for evacuation then he'd have been pilloried for losing someone. That said, it's an awful long way down from the top deck of a 747 and it doesn't take much of an imperfection in the way the slide deploys to cause a problem. Certifying the evacuation from the A380 is going to be a good game.
Incidentally, I think the tyres have to burn for 90 seconds rather than 15 minutes before the fire brigade are allowed to put them out on the certification accel-stop test. (However, I stand to be corrected if anyone knows better.)