It does say:

"Be aware that oxygen toxicity is unpredictable. Divers have experienced convulsions at shallow depths under conditions where most experts would not have expected them to occur."

But that doesn't say what depth, what oxygen % and how often it happens.

It also says that oxygen toxicity is a possibility only above 21% oxygen. In fact, with regular air there are way too many things that have already gone wrong if you are at 65 m depth (or even 50 m).

It's clear from reading the document that convulsions at "shallow depths" refers to the case of breathing 100% oxygen, where 1.5 m difference is the difference between <1.6 bar (safe) and >1.7 bar (absolutely not safe).