Yeah really I've gotta blame it on poor coaching. I know it's a short week and he's not an actual head coach etc etc etc, but really the only reason the game was as close as it was is because San Diego's offensive playcalling (whoever is to blame there, whether HC or OC) reverts to "ineffectual run, ineffectual run, ineffectual pass, punt" when they have a lead in the 3rd / 4th quarter, and that keeps their defense on the field pretty much perpetually.
Add to that the way their defense really runs out of gas (not sure if they don't have enough guys to sub, it's a conditioning thing, or if they just don't put enough pressure up to create the kind of quick plays that don't result in them running half the field every play) and I can definitely see why SD has blown their leads in prior games.
When your only hope of getting back in a game is the other team having terrible coaching / playcalling, your only offense comes with holding penalties every play, and your defense only defends the most obvious and terrible of playcalling, it's not a good look. It speaks to a lack of preparation and discipline, both of which fall squarely on the coaching staff.
(As a Lions fan, trust me, I know the look
)
So, in all, maybe the Broncos get Kubiak back and thoroughly dominate the Texans. Maybe they don't, and they get dominated instead. If I were a betting man, I'd hold off on making any wagers until I know who is in the building on Monday / Tuesday and setting the tone and pace for preparation for the upcoming game. Even if Kubiak is back for the game, if he's not back for the week of prep, I really don't see a Broncos win.