" I’ve noticed that feral druids have a similar issue with their glyph of bloodletting, which extends rip by 2 seconds (to a max of 6 seconds) when using shred or mangle in cat form.
In some circumstances, rip will fall off before its final tick. "
How to reproduce
1. Cast rip on a target dummy
2. Immediately shred once
3. Wait until rip has less than 1 second remaining
4. Shred twice
5. Rip will fall off at 1 second remaining exactly, skipping the final tick