For the record!!! No different then when I’m following an aircraft at the same altitude as me with 30 miles of lateral separation and they start blowing contrails and then stop. It is passing through moist air as opposed to dry air, I don’t know how many times I can say this. I’m also a former military pilot… If there was something on board that could be triggered mechanics certainly cannot keep their mouth shut! We would know!!!
Of course you would know. So a contrail can stop like that, instantaneously?