I don't think Israel destroyed evidence. They didn't hit the GZ but an area nearby.
By doing this it will be hard for US to easily access the nearby GZ to prove the Clown attack as the surrounding area will be on lockdown/heavy activity. (RUS/SAA)
We're 'technically' on opposite sides so it's not as simple to just go in and collect the intel.
For people asking:
GZ = Ground Zero