It is not uncommon for a wrecker driver to damage the door locks of a vehicle he/she is going to tow without the vehicle owner's permission. When retrieving your vehicle from the storage facility, you always want to check every door that has key locks, to see rather or not they still lock or unlock the vehicle.
Another way to tell if your vehicle has been unlocked, is the weatherstripping at the bottom of the glass is torn, bent or detached from the door shell.
There is really no valid reason for a wrecker driver to unlocked a locked vehicle, considering the towing industry provides all the necessary equipment to tow a vehicle. In most cases, a wrecker driver, when peering into the vehicle, will list items seen on the vehicle inventory sheet, while others will just steal what they want and write on the vehicle inventory form that the doors were unlocked.
In any event you find that your vehicle has been opened, while at the storage facility, you most definitely want to call 911 and file a report for burglary of your vehicle. If you find that your door locks don't work, you most definitely want to call the Police to make a damage report and be sure to get the offense number, so when you file a complaint against the towing company and vehicle storage facility, for damage or personal effects stolen from your vehicle, you can include this offense report number in the explanation of your complaint.
In every insurance claim filed against a towing company and vehicle storage facility, having a Police offense report number validates your claim, as without it, it's your word against the towing company, and they are known to be pathological liars.
Never, should you ever leave the Vehicle Storage Facility property if you discover damage to your vehicle without having law enforcement come and take a report. Once you leave the storage lot and notice items missing, your chance of any recovery is slim to none.