I'v shot a few with field points but always feel like I might be blowing the hunt.
I too find it hard to believe a 22 bounced off a squirrels head. I usta shoot alot of squirrels before I found bowhunting & prefered head shots. Regular 22's busted them up pretty good & holowpoints just about decapitate them. Heck my pellet gun, a crossman pump up pistol rated I think at 5 or 6 hundred fps makes it thru their skulls most times, might not pass thru but it sure put their lights out.
Squirrels are good eating if you get enuff, I need 8 or 10 before I'll cook them. Either cooking like chicken & rice or roasting the whole bunch at a low temp till theyre tender, takes a long time but worth it IMO. Sometimes I cut them up & brown the meat a little then dump it in tomato sauceb to finish cooking.