shopping cart,2 year old,... head injury inevitable

Really, who straps their toddler in the seat. I thought it was "the" parenting rule that could be broken, apparently not! So here is the story....Mt. Man had to work sunday at the bar, and I was called in. My folks were kind enough to take peanut for the afternoon, and I managed to squeeze in alone time, yeah! Mt. Man went to pick peanut up from town, and even went to the big evil store for me! :) Well, this is the scene of the accident.....peanut was wired on m&m's from gramma, and dad likes to see peanut smile. So she was allowed to "surf" in the shopping cart...don't even go there, I mentioned a few times how she likes it (in the check out line of course, never the through the whole store). So mt.man went to grab cheese for baked potato's that night, and peanut decided to try out her acrobatic moves. Luckily for her, dad has ninja like reflex's, and grabbed her pants, only to save her from the "Big" impact. Thus only for her to slide out of the new (1 size to big) pants, and smack her head on the floor. Ouch....Okay, so worried me rationalized she was okay, but daycare said that she had her head down all day...initial response, she's got a headache. Over protective, worry wort, knows to much medical...easy to overreact mama decides she should go in to see the doctor...daddy takes her....both had excellent day off together! Okay so nothing was wrong, but it would totally suck if in like a month from now something was found and it was b/c we blew it off. I think next time I'll wait for more promising signs something is wrong.