Owning your own home

They called me this evening, while at the pub, which was ideal. It turns out that they lied. The vendor was supposed to have a place to go to all agreed, they were just waiting for a buyer. This evening's update was "they've put their offer of X on the next place [that's the end of the chain] based on your offer of Y, if that is accepted then we will accept your offer". Wankers. My IFA reckons that means we have the upper hand (for all that's worth), which is something.

Sounds fair enough to me. Why does it make them wankers? They have somewhere they want to buy, you offer less than they need so they try to buy the next one for less to make the deal work.