The sac is really dirty from some of the debris from 2 of the others hatching. I try to clean up as much as I can between each 1 hatching but this guy was hatching while another was still drying so I didn't want to open it to clean anything out while the other 1 was still damp. I've isolated him in a little bowl lined with a clean sock in the corner of the hatching box, I got as much of the debris off as I can. He's not moving alot, just resting. Breathing seems normal and he doesn't seem to be in any pain. The only betadine I have is a half empty 2oz bottle, I don't think I have enough to dip the sac in.
My 2 cents, if it really ruptured, his chances are slim, so just make him comfortable. Could you possibly post a pic? Just next time you need to mess with him, dont bother while he's resting.