Consider the following premises. There is at least one y for which if y were a police officer, then y is drinking water. For all y, y will drink water if and only if y is a police officer. For all y, if y were a police officer, then y is drinking water. Can we infer the following from them? For all y, the fact that y drinks water does not imply that y is a police officer.
That contradicts the premises. Therefore the answer is no.