I replaced everything exactly the way I found it when I did a basic oil change. I will not rule out my own novice skill, but I took great care.......that being said, it wasn't exactly part of the daily inspection routine.
Always possible vandalism, and can't watch it 24/7. If I know when something happens, maybe I can talk to people or see if a camera was running...but this one did not manifest until around Sunday at midnight after a long days work. If I didn't exit the highway where
I usually do would have experienced this all on the highway as I didn't spot it until I was on regular roads.

When inspecting it in the future, at least I know about the O-ring and how it locks down.
I know I haven't liked 100% how the saddlebags set on the PCX. Visualizing a hard leather corner poking at the dipstick cap thousands of bumps....again it should be locked, but this may be a variable where I am one of a handful of guys with this brand of saddlebags setting on this brand of moped.
I'll maybe snap some photos this afternoon. Really felt like Ghost Rider out there, smell of burning saddle bags at midnight. Crazy.
And thanks for the suggestions everyone! It helps.