You cannot resupply a partially down HQ, but can resupply a fully down HQ.
I suppose it is the wrong way round, but consider this -
How harder is it to take it down just 75%, than totally destroy it. IMO it is harder to put just the right amount on it, than to totally carpet bomb it to death. Perhaps that is why the resupply model is as it is. How many HQ raids have meant to take it down 75% and ended up killing it totally?
Funnily enough was expecting a new post (not this original) and a Rook whine on this after Monday.
By killing their strats (city, ammo, training) then taking their dar down 75%, they had no dar for something like 4 hours. Of course killing the t+s and ord on the field kept them bottled up. It wasn't until we stopped that they got back off their main island.
Bish are used to flying without dar, we usually have it so little, if you can't get on local channel or squad and ask whats going on then I don't know what to suggest.