>PS: As far as I becoming the fall-guy, I will make it clear in the next meeting that the decision is not mine. I was hired to make a recommendation and that is exactly what I will do. Besides, I didn't hire them, so I don't have the power to fire anyone here.

IANAL. Having said that, it seems to me the most important thing is what you put in your PS. There is a contract between your client and the contractors. Your client, not you, determines the disposition of that contract. You are not a party to it. You made a mistake in letting your client say that the decision is yours (even effectively). You need to get that straight with your client BEFORE the next meeting so your client can correct himself to the contractors.

Presumably the contract allows for termination for non-performance by the contractors. If so, your client may do so; in turn, the contractors may sue your client if they feel they are performing as specified in the contract. In that case, the result will hinge on whether there are sufficient grounds, as per the contract, to terminate for non-performance. Your client takes the risk that the grounds are sufficient. To help him sleep at night, he hires you for an expert opinion.

A lawyer might get creative with what I believe is called "tort law", trying to argue that you advised your client maliciously or that you stand to gain from the contractors' loss. As others have advised, talk to your lawyer about this.

If you prepare a formal evaluation for your client, presumably with deficiencies listed, make it "legal grade" - if your client is non-technical he will probably pass it along verbatim to the contractors as grounds for termination. If you do your job right, the case will be so strong they won't bother paying their lawyers to second-guess them.