On guy in the class I started with was (as I recall) around a week from graduating Marine OCS when he broke his leg, which washed him out. I guess I never really asked him about that one. I understand that one of the other class DIs was one of his DIs at Marine OCS. Anyway, one of my graduating classmates was within days of our commissioning date being six months from when she reported, I think she had trouble with shin splints. Be careful about trying to push through shin splints, one guy who was with the candi-O class when I reported had stress fractures that had developed and he was there well after I graduated (on the other hand, by holding out until candi-O phase he had it quite a bit easier; each case varies, of course). Funny thing about the girl in our class was that it wasn't long before she know more than the candi-Os, and sometimes MasterGuns (awesome guy, retrospectively, I'm sort of glad I had a little time in H with him) would come to her first when something needed to be taken care of. As an aside on H classers, listen to them, take their advice with a grain of salt, but do know that they're likely to know more of what they're talking about. Some of them have attitude problems, sometimes that's why they were in H, but they can save you a lot of time and trouble. In every class there are always some who think they have things figured out for themselves and don't want to take advice. With that attitude you'd better be right; more likely you'll be learning some lessons the hard way.
Finally, I don't remember ever having to bear crawl, duck walk, or anything like that to the chow hall. No sir, gunny Carson always marched us there. Now, early on it seemed like we had a lot of little detours, I think there were couple days where we eyed just about every inch of grass between the PT field and chow hall up close. I think he could have found ways to stretch the trip so we'd have arrived just in time for lunch if he'd wanted (he had a way of doing that, took him forever just to show us through the battalions that first Saturday).
I don't know when you went through OCS or if this is the same girl, but there was a girl who graduated in our class who had been there just shy of 8 months for shin splints and stress fractures.
Needless to say, her nickname was "The Ocho".
Also, there was a guy who snapped his leg on the out-PRT after fighting through shin splints. He officially became a candio at that point and waited out graduation. He stayed in pcola until he healed after commissioning. Sometimes people risk their health/safety with a prudent decision. Possibly injure yourself and end the suck, or hold out in medical and possibly roll/continue the suck.
And yes, it was uncanny how the Gunny's (And a very special SSGT) could time our crab walking/bear crawling/star jumping from the PT field to chow so we would show up JUST on time....amazing!