Mechanic cut my fender liners - should I be upset?
 

Hi. First post here.
Recently (Jan '22) I had a blocked catalytic converter on my 2010 Pathfinder LE and had both front banks replaced. I picked the truck up, and drove it on a short trip. The SES light came on shortly after starting, and a new rattle was also noticed. I returned from the trip, and took the truck back to the muffler shop to have them look at it again. The shop owner was straight forward in admitting they had forgotten to tighten the 02 sensors, and would take care of that for me.
Fast forward to last weekend; I am getting ready to replace the front struts, and was putting penetrating oil on all the bolts in preparation. When I started to work on the passenger side I noticed that it didn't look the same. I had just recently replaced the flywheel sensor, so I was intimately familiar with the wheel well. The mechanics had cut large sections out of both front fender liners to access the 02 sensors!
https://cimg4.ibsrv.net/gimg/nissanf...e89d9e8b82.jpg
My question is "should I be upset about this?" I feel like they should have asked before cutting parts off my vehicle. I just took that liner out, so I know its a simple process, with probably no more than 7 screws.
I didn't notice this when I initially picked the vehicle up, so I am assuming that this happened when they had to go back in a tighten the 02 sensors they had left loose.