you are giving the just the right advice to David. David should get a second opinion, why not.
And again about the famous LFO : as Mark says, if the developer sends your lawyer a letter calling you to come to notary and pay the balance , give him instructions to appear before that notary with the banker’s draft (alternatively, if you are paying with a mortgage, the representative of the bank should appear at the notary to declare that the finance and moneys are ready for the completion).
Doing so the developer will find almost impossible to cancell the contract.
Aifos is very keen on doing this abusive practice , you have to show your teeth (as we say in spain) to this most unprofessional developers.