In the present Convention, genocide means any of the following acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group... - UN definition

Consensus on the matter seems complex and I'm not an expert, but what I believe is the issue is the exact definition. The grey area lies with the intent of Israel, as they state they are aiming at Hamas military targets while actually having (bizarre levels of) collateral damage.

But by this definition, one could mass murder any number of people at all times, as long as they have not spoken out their intent to do so. It's just word play at that point.