The mother was connecting through Hobby for an international flight. She more than likely wanted to keep her stroller for use in Houston to transport her kid between gates. Gate checking the stroller would have been a problem in that regard. This is where the lack of empathy comes in to play. You have a mother traveling solo with a baby for at least 13 hrs...At some point the FA needed to ask himself is this was the time to be a total douche. BTW, the PIC should have booted the FA, he was in no frame of mind to be flying. They should have also deplaned the giant...even justified, you don't get to threaten someone physically. Now, had he gone forward to file a complaint, that would have been excellent.