Pool Liner

I have 18 x 36 inground vinyl pool that is being finished this week. At the top of the pool, in the corners, the vinyl liner is not tight against the wall of the pool. Is this normal or will it stretch into place? I am afraid that if it stays like that it will puncture easily. Please give me some advise. The pool guy should be finishing up today and I don't want to let him go, if this needs to be fixed.
Thanks
Casey

I had a in-ground liner pool installed two years ago and had the same concern. The corners are supposed to be like that and I have not had a isssue with them ripping. Enjoy !

Thank you.