A deposit is not needed for a legal contract to be binding. If there is a sense of completeness in the contract (ie. price, pick up arrangements/date etc) then the courts can enforce a breach of contract and provide a remedy.

Phone records are not needed either. There are many cases where they are not available. One thing that must be known is when the offer and the acceptance were made. (Not a specific time but more like who made the offer and acceptance).

Caveat emptor is more relational to the situation where you would have bought the ute Coops and then not got what you paid for. (In private purchases)

If you have any further questions just ask me. There maybe further facts such as conditions etc that could be of use.

The point is that this guy would likely be dog's dinner in a court of law as you cannot back out of an agreed contract like that. All telephone, letter, fax etc contracts are as good as a written one. Once acceptance is complete, a revocation is not possible such as the phone call the night before.

Cheers
Brock