Yes oral contracts can be enforceable, but (i) there are limits to the types of oral contracts that are enforceable (see statute of frauds) and (ii) even for an oral contract the parties have to show that both sides clearly intended to be bound by a contract (there are some exceptions to this, but they do not apply here).

From what I read it seems that neither party treated the relationship as if they are bound by a contract. On the contrary it seemed like they proceeded under the assumption that they will negotiate some type of a deal in the future, but currently did not want to bind themselves.

None of this is legal advice, etc.