Not the same, but I was in one of the ruins in Act II and had a treasure goblin get away due to me running into two packs of elites. One was Arcane Molten Frozen, and I don't remember the other.

Anywho, I'm makin' tracks to keep my life, and ran across one of the bridges that has the set animation of half of it collapsing/breaking away. The first pack got stuck on the bridge, keeping the second pack from getting across as well.

This was about the same face I made when I realized I could exact my revenge on them for having cost me a treasure goblin.