It appears it must be that it's at the judge's discretion of whether or not questions are allowed.
In those 3 states, incl. FL, it's required by law though. The other 5 states are at the judges discretion to allow or deny them. The judge must have addressed it another way in Anthony case, outside the eyes/ears of televised audience. The lawyers & judge still review each question as to it's appropriate value to the case as well as being within the letter of the law RE exactly what witnesses may be asked at all. It had to have been addressed in some fashion.
Let me do some searching for anything that might have superseded this law between time of passage & implementation in FL and the Anthony trial. I'm sure there's a window of time between these two events. I'll see what I can find online about it.
I'm wondering more and more about the camera & case and it's role. Introducing the camera during his shower was either a ruse to get him in this vulnerable position, or he was under threat, with the gun on him. Everything on that camera card had to be destroyed or the sneaking into Arizona was for nothing. Her taking the pictures was pure fiction, they were never meant to see the light of day and she knew this. I'm trying to work up an idea on her surprising him in there, as if she had left. and returned as you suggested.
So the sleuth in me continues to try and work out these parts that we will never know for certain. This case has everything including the bathroom sink in it. Let's not look in the kitchen!