Your executives are completely unable to evaluate the products they decide to buy?

If so, yes, they are to blame, either for not being able to evaluate the stuff they buy or for deciding on questions they are not qualified for. Either one is incompetence.

You can also blame them to continue renting the thing (because it's not brought) after it's shown to be defective. And if they decide to do irreversible transformation to your business before verifying that the thing even works, than yes, that's bare incapacity of running a company.