OK, agree, when I posted I hadn't looked at the Linden status report.
"We have finished updating main grid regions with a fix which should reduce incidence of teleport disconnects. ". Mind you, 'reduce' is not the same as 'eliminate' which is the solution I would prefer. Looks like the band-aid solution.
Hopefully they've now added logging to the process so that when it happens again they can identify and fix it faster