It would be dishonest and absurd to claim that the Gophers would've lost to Central Michigan in 2015 if Kill had been healthy and the head coach for that game.
Now 2016 is a different story, and would be very interesting to know what would've happened that year if Kill had been healthy and never stepped down.
For example, I absolutely believe he would've kept Limegrover, and likely kept him as the OC.
However, I personally would still give Kill partial credit for the 2016 bowl win over WA St. He didn't coach that game, he didn't coach the team that season, different OC, different DC (technically), etc. But it was still largely his foundation, staff, players. So that's my take, which isn't worth anything I know.