And I see your Eastsideboxing source regarding the glove tear and raise you this:

Remembrance: Trainer Angelo Dundee Was At His Best In The Corner For Ali, Leonard And More

I don't like Kevin Iole but he is Yahoo Sports top boxing/mma writer. I don't think he would subscribe to an urban legend or myth.

And here is another article recounting the events as well:

Angelo Dundee never forgot his Philly roots - Page 3 - Philly.com

BUT...I could be wrong.