Sounds like they are implying he did all that spraying while all the windows were closed which would have left an accumulation of the propellant in the cab.
Gee. If he was trying to clean out all that odor from all the previous smoking in his truck, he should have stepped outside to have that smoke rather than begin stinking it up so soon after taking the time to clean it. Now, he has a MUCH bigger cleaning bill. lol