If a traveling UA pilot informed an FA and a GA noticed it even earlier...they should have taken care of the problem before a passenger had to speak up.. the employees are empowered to make those calls and actually it's a little baffling why they didn't earlier especially if they were willing to go to the trouble of recalling the jet bridge after one complaint from the OP.

Really gross! It would have been more compassionate for the poor guy to help him get cleaned up beforehand as well...or, at least direct him to a place where he could clean himself up and buy some adult diapers.