couple with their own private time bubble (early Merc retrograde)?

So last night I ate dinner at a local restaurant. Previously I've just been there when it was a buffet, but last night it wasn't one.

There was a couple near me who got served someone else's dinner. They questioned the waiters about it and both tables did end up with the correct food shortly thereafter.

Then when the waiter handed me the bill he said 'Thank-you' which felt a little odd, but whatever. I open it and it's got an unfamiliar credit card already in it. It was the other couple's bill awaiting signing. So I passed it over to him.

Asked for my bill and got it. (I also did get exactly what I ordered, quickly enough that I'm sure it didn't make any detours.)

So the common factors are the wait staff and this couple. Since the incidents only involved other people as peripheral to this couple I suspect it was something about them throwing the staff off and not generalize staff mistake-prone-ness.

So I'm fantasizing about what might make them such vortexes of confusion...