I've only had one snake ever bleed and that was his skin getting ripped. I would change his bedding to paper towels to see if it's an ongoing issue
throughly inspect the body head and vent. Any redness in the vent area?
while ya have him out might as well sterilize the tank/tub.
Blood is not normal in a shed by any means. It's most likely a scab that pulled off. When they shed their scabs shed also and they regrow the scab.