well, some of it has been rubbed off on the front wing, so they did not take care to prevent getting paint on themselves.
someone has written in it on the windscreen, so would have paint all over their hands when the police turned up - stupid.
the spray can is blue like canned snow!
paint from a can sprayed like that would run. If you have ever used it, you´d know getting it not to run can be tricky. Vandalising somebodys car, certain they´ll report it to the insurance company (and the police cos the insurers will not pay without a police report) but taking time and care not to let the paint run...
... and whoever took the picture probably sprayed the car, cos if it was paint you would take the cans (evidence) with you and if you wore gloves you are one well prepared vandal.
the evidence suggests snow

and if you zoom in on the the reflection in the headlight you can see the guy who took the picture is dressed as SANTA