[josefresco]

You proposed the method, which means you should stand behind it's success or failure. It's also likely that your client based his/her decision based on your expert advice (which is why they hired you)

However I know many consultants who simply bill for their time no matter what, even if the path taken leads to complete failure or results in time wasted.

[DaFresco]

I totally agree. What whould your suggestion be in regards to the consultants who bill no matter what. How to prevend such a thing? I guess a clause in the contract is a start.