Aside from all the implausibility of the technical aspects of what started the fire.
I can’t get over the husbands behavior.
Supposedly he was awakened and told his garage is on fire. Even if he thinks his wife has taken a taxi, how does he think the fire started? Does he think that something just ignited out of the blue? Does he think that some kind of garage thief broke into his garage and started a fire?
Does he think that since he never actually saw his wife get into a taxi cab maybe he had better make sure she wasn’t driving the car that morning or previous evening?
Sorry but his behavior is not rational.
Check the video here:
http://www.woodtv.com/dpps/news/national/south/dc-lobbyist-found-dead-in-burning-car-nt11-jgr_3694925
video of husband 57 seconds into video