When a 'oner' goes sideways: Adapting to save complex shots?

Hey everyone,

I'm Chris, a Key Grip, and I'm currently on an indie feature where we’re using an ALEXA Mini for a lot of our key scenes. We had this incredibly tricky oner planned for tomorrow, a character moving through multiple rooms, interacting with props, hitting marks perfectly, and all of it timed to a dolly move. Think a simplified version of that long tracking shot from 'True Detective'.

We spent days pre-lighting, rehearsing without cameras, locking in the marks, trying to make sure our LS 600d Pros and PavoTubes would be in the right place at the right time. Our DP and I, along with the AD, felt pretty confident. But I've been on enough sets to know these things can unravel fast once the pressure's on.

My question is, for those of you who've been there, when does a meticulously planned 'oner' or complex blocking sequence just fail on set? Not just a few takes, but the whole approach? And more importantly, what’s your process for adapting on the fly to save the scene, beyond just 'shoot coverage'? I'm looking for practical, on-the-day strategies you've used when the wheels truly come off.