PBL is referring to the deceleration achieved by this aircraft taken from the FDR print-out. A very *poor* braking indeed.
That's what I thought.
However if (if) he was based on the FDR the information might not be accurate as we still don't know how slippery the runway was.
What we know is that the crew
thought that the runway was slippery. And this could explain their hesitation to apply manual braking before spoiler extension if after all such hesitation showed up to be expected from a crew in the same situation.