I agree, but it is all part of the due diligence when weighing up a signing - character and application and conscientiousness play a part as well as footballing talent. We are usually quite good at it, the odd slip aside (Osvaldo!). But we may need to make allowances and take risks on this guy that we wouldn't ordinarily do, given the hole we are in at the back.
Indeed, he has all the hallmarks of a typical January panic signing!