Why would that make it mechanical? Terrorists have been known to start their plots in bathrooms before Going into the bathroom would be q way to get at the explosive material brought on board without attracting attention
that’s what I was thinking. It’d be a lot easier to assemble and detonate a bomb in the bathroom than in your seats.
What kind of smoke would be coming out of the bathroom otherwise?
Lavatories are where the so called Chechen “snukes” were set off.