Q about "Point Blank"

The SA says the Hurricane can shoot at the bomber. Firehouse is asking about other Allied aircraft shooting at the bomber. I had house-ruled that you couldn't shoot into an enemy-occupied hex containing a friendly aircraft, as there could be collateral damage. I amended it to say that if you did fire at an enemy in a hex that also contained a friendly at the same altitude, a vital on the enemy would result in considerable damage to the friendly.

The problem was that the Hurricane's special ability seems exclusive to that aircraft (in that theatre): it's the only aircraft that can fire into a hex at range zero, which means an enemy aircraft in that hex has no return fire, AND, no Axis aircraft could fire on the Hurricane for the corollary of the same house rule: can't fire into a hex containing a friendly, w/o doing some damage to the friendly. 

I think the bomber should have had range zero fire, at least. And I think the bomber's escorts should be able to fire on an enemy aircraft that is in the same hex/same altitude as the bomber, w/o hitting the bomber.

Any thoughts, Foruminians?