You know when they lock the phone lines for a sale ("Phones Locked") at the start, when this happened Steve MacDonald said something like: "We've locked the phone lines to make things fair for everyone. There's no back door (to this)", implying that there's no way whatsoever of buying an item before the phone lines are opened, yet when the phone lines ARE opened the quantity was immediately reduced by 1 due to a web bid (or "reservation"); "something that we can't control" (according to Steve).
Strictly speaking, it may be true that there's no way of buying an item by phone before the phone lines are open but to say that there's no way of buying an item whatsoever is somewhat deceptive even if the quantity doesn't change whilst the phone lines are locked. All you need to do is to place a web bid at a sensible price before the phone lines open and you have bought one of those items if the price falls to or below that web bid value, and theoretically Sit-up should immediately cancel the live sale if the number of web bids exceeds the quantity on offer before the phone lines open otherwise it is actually fraud to solicit phone calls if there isn't actually any stock left available to buy.
Whether they will actually do this on Speed Auction if they are (exceptionally) fortunate enough to get more web bids for a particular item than the specific quantity offered (if the quantity of an item was very low) remains to be seen, but they should do so.