Changing the Scale of a Model is tantamount to changing the Model itself.
Once one starts playing with Scaling it's hard to keep track of what one has and hasn't done. Unlike changing the rotation or position of a model on the build plate, scaling (particularly when used to compensate for filament thermal contraction) is frequently imperceptible.
It would be great if in the list of imported models those which have been scaled have some kind of visual cue (eg an asterisk or the word "scaled" next to them). This would help avoid errors.