In phase 3 of the beta test I know for certain that I would occasionally get the message "You partially block" when my shield was down, but this was almost after my shield arm had fallen so I chalked it up to lag and the game messing up. Also, whenever I got messages like that (and even sometimes when I had my shield raised) I would always get sword skill instead of shield skill. I haven't seen the messages messing up in OB but I can't tell if it still screws up and gives sword skill on blocks sometimes or not due to them not showing the skill gained from parry/blocks.
Edit: As for the concern about wanting Gladiator to feel like a paladin, Aegis Boon will handle any concerns you might have. Presuming it has remained unchanged you gain temporary invincibility towards blockable attacks for the normal duration of guard (sadly the trait Self Preservation does not affect the length of Aegis Boon) and gain about 40~45% of the damage you would've taken back as hp. The only issue with it I saw was that I didn't gain shield skill because the game was acting like the enemies weren't attacking me when I absorbed their hits (this included not showing any attack animations from them).