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
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.
I believe he said output volts.
Would that then make it a possibility then?
Also I should mention he tried to re-energize it by running current through it with a small 9vdc battery but it did not work.
placed near something while being shipped?

any way to shield a cart during shipping......?
A high energy magnet would ruin the cartridge by demagnetizing the cartridge's magnet which folows as to your description of the problem. Moving magnet cartridges need both sides equal - equally muscular magnet - to get proper balance.