Buybacks Aren't Corporate Executives Poor Timers

Dell spent more money on buybacks when they were a public company than their total earnings over the course of that same period. Dell had to be buying high in order to either reduce the float or issue more stock options so aren't corporate executives poor timers? I think you just buy it at the market price some yes sometimes you'll be overpaying some price you're underpaying but on average you'll be paying the price and you'll be getting the fair market value by the way.