That is how I remember it as well. Whilst this is all my speculation/inference of course, the FO and Gayle Benson didn't actually believe Payton would walk away. Winston had shown some promise under Sean pre-injury and that season was the start us becoming infested with the injury bug year after year but of course no one at the time could've known that to be the case. Then rumblings started in the media. Kamara took to twitter and completely blew it off which means he either had no idea and/or had some inkling but didn't believe it was serious either. Then Payton actually retired, and in IIRC in either the press conference or an interview done right after Gayle even mentioned that she asked he if he just wanted a year sabbatical to refresh himself. They were completely caught off-guard. Of course after the Miami situation was confirmed I would say they shouldn't of been but they had their reasons I'm sure. Not too long after if not the same day, Payton endorsed Dennis Allen as the next HC. At that point, it's safe to say the writing was on the wall unless someone else really blew them away.
This year we have absolutely none of that going on. Allen isn't endorsing anyone and even he knows with the fanbase and possibly a portion of the playing staff it would be the "kiss of death" for that person anyway. There are no co-ordinators on our staff that are remotely considered shoe-ins for a HC role anywhere, and Rizzi's had an audition that started off fun but has been lackluster since then.
I think this time they're definitely going to do an extensive search. I don't personally want either Jon Gruden or Matt Nagy to be part of that search but that's out of our control.