Definitely, there is no alerting system that would warn merchant "the blockchain you are currently using is forked", so imagining there are three parallel forks, each one having it's own criteria for accepting transactions, the same coins could be spent with three different recepients.

It is, in the end, same coin spent (meaning sent and accepted) several times. Yes, it was double spend. No, it wasn't all on one chain. But the whole chain operation is hidden from merchants (as it should be), so from their point of view, they got a confirmed operation that could get reversed. Until this is fixed, as in you can somehow automatically confirm that blockchain is not running in a forked mode, I am not sure how large money transfers could be possible.

Basically, having to wait for 6 confirmations is already long enough to barely make it useable, and it turns out this is not (always) enough and it could fail due to a simple bug. Call it FUD if you like, but this is bad news, no matter how you spin it.