Castro just highlighted a slip up.
What Castro was trying to do by repeatedly saying “did you forget?” was trying to continue the narrative and imply that Joe was losing his mind. Only dense individuals would try to act like he wasn’t doing that, which is why Castro is receiving the well deserved backlash today.
Personally The media doesn’t even need to cover this too much, Castro is a non factor and has no chance of being the nominee, let alone be a President.