Can magnet placed beside cartridge damage a coil?


I received a 20 year old NOS cart from a dealer which I resold as new but ended up having to refund the payment back to the buyer after he found it to have a channel imbalance issue.

I sent it back to the dealer to check out and he says there is a large difference in coil readings of 1.3 (normal) vs. .8. He says he tested his entire stash of these old carts prior to selling them and says the only explanation is that somehow a magnet was placed close to the cart either during transport or by the person I sold it to and thereby damaging the one coil. He therefore assumes no responsibility to replace it.

Would this be possible?
frankk
What it means is that your original dealer is a cheapskate. Yes, if you placed a really high-powered magnet right adjacent to the cartridge it could damage it, but this would almost have to be intentional. And I seriously doubt that he took the time to test each coil on each NOS cartridge he sold! Caveat Emptor applies here, for certain.
Did you demo cartridge or was it bought online? It is good to stay away from NOS unless a warranty is available. Coming into contact with a magnet seems suspect at best.
I couldn't find anything on internet with anyone having a similar experiences so along with replies here (although Stringeen says it could happen) Im having doubts.
1.3 and .8 what? Was he measuring resistance(Ohms) or output(mV)? If resistance; he's fulla shiite. A strong magnet can have an effect on a another(ie: demagnetize), but will do nothing lasting to a coil.