Here is what I know about the hire process at universities (I wrote this in another thread):
If the process is like other Universities, Haslam is likely the chair of a small committee. The committee has a predetermined survey that is used to evaluate candidates. Each committee member makes a grade for each candidate response, which are summed to give an overall rating. These ratings are then summarized by the chair of the committee and a report is sent to the Provost. Given the importance of the hire, the provost then also makes a decision and reports to the BOR. The BOR makes the final decision.
With that written, given that Haslam is a Dean, the people above him would usually defer to his decision. Thus, I can see why he would say it's his decision. However, regardless of opinion, Hauck comes with a history that may give pause to the people above Haslam.