Someone in the chain assumed that there were spare 3090s and just stole the card that came with the block. Obviously for a cheeky tech makeover bit.

Maybe the reason that it turned up again recently was because they saw everything catch fire, panicked, and put it back?

Either that, or LMG's logistics just put it in a general GPU pile without putting it with the cooler, so when they couldn't find it with the cooler, it was assumed lost.