There are people who hang out in Lowes and Home Depot parking lots and just wait for someone to leave something of value. I've seen it a few times where usually a lady gets out of the car, takes a look at something on a truck bed, then makes a phone call. This is how they get in and out so fast. I usually stand near my car and blatantly watch her to make it obvious I'm paying attention. Can't do much else since not 100% sure it's a thief and obviously no crime has been committed yet.
Definitely double check the cameras to see if anyone goes to inspect while on the phone before it was stolen. You may be able to get a plate on that person.