Can you be Convicted on a Confession Alone in Michigan

The reading-between-the-lines element for me is that this was most likely a "cold" interview wherein the employee confessed to what they had actually perpetrated when confronted with the facts and circumstances. It is highly unlikely that LP interviewed based on just some sort of out-of-the-blue presumption. Unbeknownst to the 'confessor' they were probably not the only interviewee.
LP most likely used a concept called 'exclusive opportunity' as a basis to initiate their interview process. And, they had facts to back up their initiation of the interview process to begin with.
One last thing, in signing the confession either the signer is guilty as sin or too silly to know the difference to NOT autograph a document that they are not guilty of.