What do you do with suspected trimmed cards?

[steve B]

The production quality and QC were pretty bad at Topps. Back when dealers had boxes full of 70's stuff just boxed with no sleeves I used to deliberately look for cards that were a bit "off" cards that were a tiny bit short or narrow I usually ignored as I was looking for more interesting ones. I did get a couple oversize cards, and some other really odd stuff. Not as often as you'd think.
Even crooked edges can be factory.

And I saw someone at the LCS pull a card from a classic pack that was literally torn in half. (The shop gave him a new pack free. )

The size of the card isn't the tell for trimming, although it can make it obvious.
It's how he edge looks and feels.

Grading won't grade anything strange, but I think that's more about appearances. Lately I wonder if they can even tell.

I do have a handful of cards I know are trimmed, but most are prewar.
Any modern ones, and I do have a handful that are are obvious. Like totally missing borders obvious.

On most commons, I would just relax and call it Topps being Topps. There just isn't time to obsess about measuring every card.
In general, I'd look at the circumstances of how I bought it. If it was a single card I was buying for full retail, then yeah, I'll check a little maybe..
If I buy a box full of cards at the flea market? Not really. Something like he batch of 75s I saw a few years ago that were all over the place for size, I just didn't buy.