I noticed a BA flight I wanted had one Business Class award seat left. I tried to book through Iberia (for the promotion) but was unsuccessful at the payment stage. I then managed to book it through BA but had to wait well over an hour for it to appear on BA! Which got me wondering:

1. If there are 6 customer-facing steps in the booking, at which step does the booker have a firm hold on it, ie no-one else can jump in and book it?
2. How long does this hold last for if the booking is not completed? Is the answer the same when booking BA through Iberia as when booking BA through BA?
3. Does the release of that hold take place automatically and the seat re-released to the public, or does it go back into the pot like a cancellation of an award ticket and risk not being made available again?