You shouldn't hang a bear canister because since the bears know how to defeat a hang, the canister drops and -ta da- might be compromised just as if it was pushed from the ledge.
We actually chatted with the bear ranger in Yosemite about that bear at the start of our trip. He told us the bear was actually maneuvering the canisters TO the cliffs, sometimes rather large distances actually..the people were not putting them near cliffs…then pushing them off. He said it happened numerous times and warned us to wedge our canisters between rocks and not just place them on the ground as you are normally supposed to do.


