This is the very reason I do a '480 Special' in my rough-ins.
I take the box that has the home run, and pigtail the hot and neutral together with an orange wire nut and stuff it in the back of the box.
When I come back to trim, I just remove the nut, separate the two wires and cap them off.
If, as in this case, I am not allowed to come back........well, you can easily imagine what's gonna happen. Unlicensed hack puts in all the devices and throws the breaker. BOOM! BOOM! BOOM! right down the line.
NOW who's gonna get a call?
YOU! I know, the HO ain't gonna be happy, but all I would say is, "Well, Mr. Smith, I'm sorry that you're having problems. But if you would have allowed me to finish the job, taking care of these problems would have been my responsibility to fix. However, since you've breached the contract, I have no choice but to charge you $xxxx to come out and locate and resolve the problems for you. When would be a good time for you?........"