|Yes they could.|
I know some folks that have a huge truck with all sorts of add on stuff. Lift gate to alarm to backup camera.
We looked at almost every part and though I couldn't get to the wiring of the backup camera I suspect it is the cause of the dead battery.
You'd have to find out how it was installed. Usually there are two parts and you have to disconnect both to at least test this.
Problem is that once you run down a battery it can't be trusted either. Run a load tester on it to be sure. Most auto parts places have a small free test to check battery. They never use safety glasses but you need to when they test it or be far away. It could explode.
Why did it take me over a year to phone in a problem to ATT?