Nothing a heat gun cannot correct in short order. I've received many planes that way.

An experienced hand can fix that in a couple of minutes... the problem lies with newbies trying to do the same.

They are not used to dealing with covering temperatures and will either set things too cool, or too hot.

The temperature range between a good fix and failure is quite small.

The gun has to be hot enough to bubble up the covering and start the plastic stretching, but add just a bit more heat and the covering will melt and rip.