Help settle a debate between me and my wife.

We have a nonstick all-clad skillet. My wife has been known to put metal pans on top of this skillet for storage (eg. putting a small stainless steel pot on the surface of the nonstick skillet). I told her to avoid doing that and make sure to put a towel between the two surfaces, even if the pot is just sitting on top of the nonstick because it could scratch it if it got bumped or shifted or anything; better safe than sorry.

Then one day I was using one of those black plastic ground beef mashers on the non stick skillet and she goes, "that has to be way worse for it than me setting a pan on top of it!" (because of how much I was mashing with it)

As far as I know, these plastic utensils are exactly what you're supposed to use for non stick.

So which of these two is more damaging?