Mack ought have one responsibility only. To the kids he recruits and coaches. When he's the coach at Texas, he's able to tell them what he can commit to them personally. When he isn't, he can't.
I expect when he recruits kids he tells them to look around and find what's best for them. He also makes a pitch for what he's got to offer. Once he's fired, the first part still applies.
Mack is, in my opinion (and also supported by the record books), the best coach to this point in Texas history. It's a shame that people go to such great lengths to change the record and sully that legacy. Among his many accomplishments, providing honest guidance to young men is among the most important. Encouraging them to do the best they can for themselves is always the advice that should be given.