I like this idea.  A lot.
However,... I think there should only be a penelty for the HO, and not the others.  All of the other "downers" are a natural part of this game, while the HO is well... grrrrrr.  
I'm not sure how this would be coded though.  Dmg is dmg to the server, and a collision isnt always a HO.  I've had more than once an enemy plane run up my tailpipe while trying to get him to fly past me (likewise, I've done it to others).