The fact that it's a 180° rotation is also interesting: the H2O panel is mounted upside down (unlike most other Kobo devices, except the Aura HD and possibly the H2OČ), so Nickel actually runs in a specific rotation designed to handle that, which doesn't match that of other devices (rotate 1 vs. rotate 3 for others).
This is interesting because the only other source of rotation shenanigans is the boot process, and pickel, and both are Landscape, so the other two rotations lefts (0 & 2).
Which means it looks like its definitely nickel forgetting itself and thinking it's running on something that's not an H2O (for some reason).
Or something.
.
NOTE: I say "upside down" relative to other Kobos. NTX mounts panels in a weird-ass native orientation that is definitely NOT Upright Portrait.