Us (2 defiants) were chasing them (3 lower level guardians on the run) and they ran up a mountainside, we chased after them, and they used a push ability to knock us off the mountain and we died. They kept baiting other defiants for 10 minutes to follow up the mountain, and continually get pushed off and die. This in my eyes is exploiting, and I think it would be necesarry to null fall damage on your target.