Yes you can eat undercooked pie crust as there's nothing harmful in the undercooked pie crust that would cause you any health issues.
The undercooked pie crust may not taste as good as fully cooked pie crust but it certainly will not hurt you to eat the undercooked pie crust or even the undercooked pie.
If the pie crust or the pie has not fully cooked and it's still warm or hot then just put the pie back into the oven and cook it for a few more minutes until the pie is cooked.
It's not recommended by most people to eat undercooked dough or undercooked pie crust because of the potential for Salmonella Poisoning or E Coli.
But I've eaten undercooked pie crust and raw dough including raw cookie dough before and never got sick but there could be the rare chance that you get sick.