I don’t really know to be honest, I presume you’re right and it’s clamped, but is the whole design purpose of Log gammas not to fit as much information as possible within the bounds of 0-1 values? If so, and the look LUTs are designed to work on a Log input I don’t see it as a major issue.
I edited all these Play RAWs with my double LUT technique (the Log conversion is always the same, the look LUT varies here and there) and for my tastes I don’t feel as though I’m losing anything in the highlights:
Some of them could afford to have slightly stronger blacks, but my tastes were obviously slightly different at the time and it’s easy fix if you wanted to.