What with most fuels being "up to 10% ethanol (what we used to buy in wee bottles labeled: DRY GAS), unless you had a REALLY BIG slug of water... which actually would have frozen if cold enough, I don't think water was the issue.
Could have been the car was having what I refer to as a moment of "Digital Stupidity"... kind of similar to when your PC (or whatever 'puter you're using) plays the time honoured game: "Ignore the Human".
Of course, what the the X-charger install imminent.... as usual with this sort of thing, the timing is EXCELLENT!
Hopefully, as stated... just one of those "Gremlins" that pop up unbidden.... and vanish from time to time.
I get something similar.... every once in a while... in nothing that could even be considered a regular or predicatble interval, I get the odd misfire. Not enough to throw a code or anything... just a wee "blip".