Hi Rex,
Nice analysis, I totally missed the obvious interference.
However, interference is not checked before the HO is done, so the BSC shall still propose the first neighbour as the candidate.
Unfortunately, it is really difficult to know why the BSC didn’t choose it here, because there are so many variables to take into account (previous HO ? load ? LINK FACTOR ? PRIORITY, cause of HO ? etc…)
Pix