No, he thought about that already, and it isn't a valid reason at all to let her live.

But looking at where she stands he could make life a bit easier on himself by just letting her fall to her death. People fall off high places all the time, he wouldn't have to do anything to hide how she died.

He growls, slowly walking towards her. If she tries to escape to either side, she'll find him leaping forward, not quite lunging at her but so that he bars her way and can try to shove her off the top of the building.