Verizon Sales Manager interview questions

Interview process consisted of initial interview with hiring manager. This was followed on a separate day with interviews with two of his peers from a different organizational silo. All of this was followed by an HR phone interview where I was asked questions for a half hour and then presented with an offer. I thought this was strange. What was the point in wasting our time with a bunch of behavioral interview questions when the hiring decision had already been made? I had 48 hours from the time of the offer to take a drug test. This was a managerial position, and at the time of the offer, I had not had an opportunity to meet any of the individuals I would be managing.