Many years ago I had a 10 ft. boa constrictor attack my wrist and begin to constrict my arm before trying to eat my hand during a feed with tongs that were too short. I got it off the feed mode by spraying it's head with cold water, leaving similar gashes that you received. It looks like your healing up nicely, but having a cold water spray bottle nearby may be useful when it gets hairy :-) Nice boa constrictor btw!