Heard about a similar situation. The highest bidder pulled out and the EA went back to the second highest bidder. He refused to match his previous bid and put in a lower bid. The EA had no problem with that, took the lower bid and left the house on the market a while. I don't know if that lower bid was the final one or not.
If I were you, I'd ring the EA up and put in a lower bid. If he goes on about how high your bid was the last time, simply tell him interest rates and the market have changed, and you're now only prepared to bid your current amount.
It might be a good idea to get someone else to ring the EA first to enquire on any current bids, and also to ring a few days later to check again.