As for the chips, they were stored at room temp. It hasn’t been that warm in Canada this summer. I don’t think that the temp ever went over 65 in that room. There was also no direct sunlight.

Sounds alot like Wisconsin... no Sunlight, no heat.

Could they have been exposed to heat on the way back from the convention? Or maybe the reaction was started before you bought the chip and just continued after you took it home.

This isn't uncommon, to have red chips bleeding, (I have pages with marks and flips with marks) but considering your storage and just being stacked with other chips, it's pretty strange.

Are you going to try to remove the stain?