I agree.
In fact, marking with tape would be just as much of a violation as no identification at all.
Besides, this was not always code required. I know most of you do not like to do “code” so calling it out without knowing the installation date is trivial.
They say tightly bundled wire causes heat buildup. He can work on my panel, but no zap straps, thanks anyway. 
John Kogel
www.allsafehome.ca
Electrical Inspector nailed me 20 years ago for using cable ties in the panel. (Ontario Canada) he said it was not approved due to heating of the conductors. We wired panels for the phone company in that fashion if it was not neat they would have a fit. Believe this or not they even inspected the finish on conduit.