That was a bit disconcerting.
A rogue terminal can decide to authorize the transaction with a “signature” (there are legitimate uses for this)
Or even with no PIN at all (there are also legitimate uses for this)
It’s also possible to do either of these 2 things and then report back that the transaction what authorized with a PIN
Most cards aren't like this.
With my UK issued AmEx & Visa cards (both Charge/Credit), at certain places terminal didn't even ask me for a PIN, and the transaction just went through as "Chip & Signature"
Which is kinda pointless since if you are paying and receiving service at the counter - you aren't really receiving a service to tip for.
Its crazy, but kinda reasonable
Checking which corresponds to what card is the hard step because you need access to an acquirer to my knowledge, and you'll lose that access quiet quickly if you attempt too many incorrect combinations.
EMV (the card standard used by all modern chip/contactless cards) supports PINs between 4-12 digits in length.
I’d change mine too except I use the PIN so infrequently (99% contactless now days) I’m worried I’d forget the new one!