The first clue was the fact that the daughter was screaming for help.
To be fair, the pipe incident had daddy investigating 'wierd noises'. Given that I doubt he normally carries a length of pipe around, said wierd noises were apparently enough to make him feel the need to arm himself.
The second clue was the fact that the guy was holding her at knife point.
That and the latex mask/gloves combined with extreme age difference.
Similar points:
Disturbing noises - Strangling Dad wins with actual screams
Strangers - Neither dad knew the perp before the encounter in/around their daughter's bedroom
Naked - Strangling Dad wins with the added creepyness of mask/gloves.
Dissimilar points:
Criminal record - The guy who got strangled had a criminal(sexual) record, the one hit with a pipe presumably didn't.
Consequences - the guy who was actually attacking got killed, the one who was merely trespassing got a nasty hit to the head.
Age of presumed victim - The daughter of the strangler is a legal adult, at this time the daughter of the pipe wielder is a minor.
Honestly enough, I think the two incidents being examined had proportionate and fairly reasonable responses. I think these incidents point towards letting ALL the adults know that you're staying over night, lest you be presumed an intruder.