The Columbus Dispatch is reporting that the lawyer who contacted Tressel was former-OSU walk-on Chris Cicero, whose time at OSU overlapped with Tressl's time as an assistant at OSU. Cicero, apparently, has a history of unethical conduct, which is not remotely surprising as he probably should not have been talking to Tressel in the first place.
There are a lot of ways to interpret this information. But even if we take Tressel's word that his concern was for maintaining confidentiality, it appears that Tressel chose to keep quiet to protect his former player at the expense of the institution and with clear disregard for the rules. Now, while this is in some way understandable from a personal standpoint, it is completely indfensible from a professional one.