You need some more info about contrails. The article is aimed at “chemtrail” people, but the contrail info in the links is very informative.
http://www.tetrahedron.org/articles/health_risks/Contrail_Controversy.html
Contrails can persist for 10 hours or more, depending upon temperature and humidity. Those can change even when a plane is at a constant altitude.
Search on “contrail persistence.” Do image searches on “contrails” and “wide contrails.”
I did as you ordered, for about an hour, but I neither saw, nor read, anything that would make me think differently.
Has anyone bothered to check whether the UPS plane changed altitude, or, if the OAT (at altitude) changed over LA, or even humidity? OR is it easier to just ASSUME that such happened?
Did anyone as themselves how the UPS plane could be moving obviously faster than sound, when it passed the little cloud?
Did anybody wonder why the “contrail” is thicker, not thinner, 200 miles away (and presumably, 20 minutes later)?
DG