I agree with [MENTION=12701]boyscout[/MENTION]. This 'tech' is paid to install vents and other trim, not to make the holes behind the vent. I'm assuming, but it makes sense. It would be unrealistic, maybe, to send an entire trailer back up the line to have a hole cut. Or what a hassle to bring the hole cutter down the line to do a missed hole. (read with sarcasm) Although you would think they could come up with some tagging method to mark stuff like this and have it resolved when the trailer gets off the line. Of course if the 'tech' didn't install the vent cover it would have been caught during final inspection, maybe. But then the 'tech' wouldn't have been paid piecework price for the vent because it was still on their workstation at the end of the day. The RV industry, in general, uses a manufacturing model and compensation system for their workers that is designed to crank out units. When things like this happen they don't get fixed because everybody on the manufacturing side loses. It's not like the movie scene where an automotive worker can pull a rope to set off the alarm and stop the production line to fix an error.
My determination has been that if someone wants a perfect to near perfect RV they need to look at the number of units a manufacturer makes in a year and what their compensation method is for their assembly workers.
I guess your silver lining is that nothing was smashed. Yes it is disappointing, but based on problems others in this forum have had with their rig this one is small.