Hi,
DW
It's possible that the PF either never heard or failed to understand the consequences of the PNF's "Alternate Law" call, but the idea that the PF believed the hard protections were still active can never be anything more than speculation.
This speculation seems to still be the most plausible
In fact it is supported by the fact that the pilot continues pulling on the stick despite the stall alarm and the remarks of the PNF
More .. the PF never acknowledge verbally the PNF "Alternate law"
A "normal" pilot (pilot knowing the Airbus flight laws) can do this if it has (or thinks) the protection in force