When wholesaling why not write an option contract?

I spoke with a lawyer in regards to the idea of "wholesaling" properties and his take was to just write an option contract outright rather than create what is essentially an option contract by including an escape clause? Any thoughts on the legal implications of this? Specificallly in regards to how the courts view such "purchase contracts" which are in essence functioning as an option to purchase. Does anybody know of cases where courts have found such lines as "contingent upon partner's approval" or "contingent upon securing financing" to be weasel clauses?
If anyone can provide some insight into this it would be greatly appreciated. At this point I'm deciding which path to take; outright option contract, or purchase contract with an escape clause. Thanks in advance!