An interesting ruling at the 'Shoe - What would you do?

I got murdered during my session last week.  All in on the turn with the flop nut straight?  Rivered flush.  All in on the flop?  Turned flush.  All in on the turn with bottom two pair?  Rivered trips.  Wah wah wah.

Anyway, an interesting hand occurred midway through the first orbit of my miserable session.  Here's the recount:

Pre flop cards are dealt.
As the dealer completes the deal, the dealer somehow knocks over the top two cards, one of which flips over face up -- a 4 of spades.  The dealer is unsure which card is the top card (i.e. the burn card) and which should be on the flop, and the players were not closely observing the dealer to know which is which.  At this point, action has completed in 2-3 spots (UTG called, 2 others folded).  Therefore, I think "significant" action has occurred and a misdeal cannot be called.

What do you do in this situation?  To sum up, 1 of 3 pre flop cards have potentially been exposed, or potentially the burn card has been exposed.  A normal rule for prematurely exposed board cards is to deal out and preserve the natural order of the deck (i.e. if the turn is prematurely shown, deal the river as the turn and and then reshuffle the deck).  In this situation, the partial flop is prematurely exposed.

Floor is called and rules to take other 2 cards off top of deck (the natural 2 remaining flop cards).  Floor rules to shuffle them into the 2 "exposed" cards on the table, meaning the pending action has the advantage of knowing that 3 out of 4 times (75%), there will be a 4 on the flop, whereby the prior action was not able to take advantage.

Personally, I think this is the worst response, but in the heat of the moment, the floor had to make a snap decision to continue the game.  No shame on the floor; he's caught in a tough spot with a situation that likely has never occurred before.

In thinking about it more critically, and talking with the table, there are quite a few solutions:

1. If you just shuffle the 2 "exposed" cards, you at least lower the odds to 1 out of 2 times (50%), lowering the remaining players' advantage, while preserving the natural 2 out of 3 flop cards.  This solution makes it more "fair" to the players that have already acted, albeit still giving the players to act a huge advantage.
2. Reshuffle the entire deck to a new flop.
3. My optimal opinion to the solution: deal out the 2 flop cards, the burn & turn, and burn & river to preserve the natural order of the turn / river, and then reshuffle the entire deck with the two "exposed" flop cards.  Burn the top card of the newly shuffled deck and flop the unexposed top card.  You've preserved every card but the first flop card.

I'm not sure what the proper procedure is here as I've never seen this type of thing happen.  I'm sure most of you have seen more hands than me and seen this before; what was the ruling in your room?  Can you think of another solution?  Thoughts?

FWIW, I raised my AQo, got a host of callers and check / folded the flop with the 4 3 4 flop when an opponent with 88 led all streets -- 5 hit the turn, 7 hit the river and the 88 got stacked by 66.