Simon,
What explains, for instance, that the 2005 expired pan-f I shot recently is perfectly well developed and even has the manufactured markings bright and clear while fresh Pan-F often comes out washed out?

Under the above circumstances, the "latent image" theory just doesn't stand.
My error? Maybe. But hundreds of posts on the internet from people having the same issue can't
possibly all be wrong at once. And even you acknowledged the Pan-F issue. But if 2005 film behaves so nicely and fresh film does on an aleatory basis, what is the explanation?

Unstable film? Maybe. That would make it a manugacturing issue.

I would tend towards another theory: selling not so fresh film with a stamped dates that show it's fresh. Maybe? That would make it a QC issue.

I would really apreciate an explanation on why this film behaves so erratically. In my case, the latent image stability theory has been proven wrong many times.