Aww... naughty Hank!

It sounds like Hank might have been feeling protective of his home, and his family, particularly with an unaltered boy. Lots of neutered males tend to pick on intact males. Probably jealous.

I would try to introduce them next time on neutral territory, preferably a park, or somewhere that they can either be off-leash or on long lines so they can do the natural meeting ritual instead of meeting face to face. Try taking them on a walk together, side by side. Parallel walking is one of the best ways to introduce dogs.