Hard to say. I would have thought it difficult to fire Zook after 6-6, but when you frame it as "he beat an easy non-conference schedule + Northwestern and Indiana and then when the meat of the schedule hit he went 0-6", then yes, it's easier to understand. So I could see any range of things.
Purdue's AD let Darrell Hazell have a fourth season (after a 6-30 start) to see if there was a "click". He started 3-3 (1-2 in the B1G with the 1 being an OT win over Illinois in the doink FG game) and he got fired.
On the flipside, Duke's AD let David Cutcliffe have a fourth season after a 12-24 record his first three seasons. He went 3-9 that fourth year (with a bunch of injuries) and the AD let him have a fifth season.
I don't think I could see Whitman letting Lovie have a fifth year if he goes 3-9, and I don't think I could see Whitman firing Lovie if he starts 3-3, but crazier things have happened. That Duke team came very close to knocking off two ranked teams the end of that season, so I'm guessing it was "we're almost there". And Hazell had lost to Maryland 50-7, so it was "this isn't going anywhere".