A quote from Ben Collins
"I’ve always been surprised with what a tyre will put up with. It’s a very gradual decline in grip but not at the expense of stability and again I think we shouldn’t go too far with this as a handling feature because you hardly notice it in RL. It’s so subtle – the steering is just a hint lighter and the tail is a little free on power until you tear through the cords and puncture the carcass!
When I’m being sensitive I’m listening / feeling for the rumble in the rear end that tells me the tyre block is gone and I’m wearing onto the chords, failing that the squeal of metal from inside! It’s only at this very late stage that you see a noticeable reduction in grip and it’s probably 10 seconds prior to the tyre exploding."
So they didn't get it totally wrong, i think they've just gone a little too conservative on the wear indicator, but loosing all grip in few laps should be spot on.
Also you may see better laptimes as the race goes on because the track gets rubbered in.
