The tyre and wheel are ok, there was a screw in it but it was repaired with a proper patch from inside, not a dog turd.

What seems to have happened is the stiff suspension has carried it so it just skimmed the road with no weight on the flat rather than rolling with the weight of the car on it.
When it was parked, you just couldn't really tell it was flat.


The other wheel on the axle has taken the weight like this



Only when I cornered did it then weight up on that corner and start to feel like a flat tyre.


I presume that's why the TPMS didn't go off, it's not detected any difference while driving straight and as the wheels will turn at different speeds when cornering anyway, the TPMS obviously can't measure the difference then and warn me.

I'm surprised that it didn't pick it up.

I had a screw in one of my rears and it picked it up in a 30 limit in a straight line. There was enough air in it to get me back home,where I could pump it up a bit and then get it repaired.

I'd certainly mention it when you are getting the next service