It is not unusual for a belt to look just fine but be broken. They don't usually show signs of failure to the naked eye. It would be like taking your engine apart to see if a connecting rod is going to fail. Can't tell. That is why it is so spooky. Also I agree timing belts can cause emission issues but that is a stretch. (no pun intended) A stretched belt really has no real affect on camshaft timing. If it stretched far enough to cause emission issues the teeth of the belt would not mesh with the sprocket and the engine would not run that way. Emission related components are more likely induction related, sensors, cats etc. I think if you brought your car to your dealer and asked for emission warranty when a belt fails you would have an argument on your hands..
the law/s state anything that can effect emissions mainly on autos/trucks. went into effect in '96. case in point '95 subaru legacy timing belts were rated for 60k, in '96 same car and engines, the belts were now rated for 105k miles, of course it was a different belt and part number.
your analogy of a broken belt I've heard before, from mechanics who remember the early belts in the 1980s car. GL1500 belts are completely different than those '80s belts.
bottom line honda spec'd inspection at 100k miles. I think the engineers knew what they were doing esp for their flagship model. just like when they spec'd 8k oil changes using dino oil tech of 1988.