[jamiedamien]

I suspect what happened is that the position and velocity estimates from the VIO system (cameras) were wrong (and perhaps wildly jumping) and since position and velocity errors are inputs to the attitude controller, the tilt oscillated as well. It's not that the IMU did a poor job estimating attitude (tilt), but rather that the attitude controller was asked to tilt in erratic directions to compensate for the erratic and incorrect position and velocity readings.

It's quite hard to detect when position and velocities are "obviously incorrect", especially when they come from VIO, where the optimization result can jump around in non ideal conditions, so I'm not surprised there was not a more graceful anomaly detection.