Maybe different incident, there was some reporting on another incident where he appeared to freeze but was trying to hear what those in the front row were saying according to someone standing with him. I'll have to track down the one that's got you worried.
Freezing is better than being a thoughtless criminal POS like the orange one who is definitely losing his marbles more every day, tho.
Hell, even at 67 I do the freeze thing by going into another room and going now what the hell did I come in here for? Doesn't mean I've lost anything but a thought temporarily.
Forgetting why we go into a room goes along with trying to find things we KNOW we have and where they should be. I like to think that part comes from reorganizing an area and not thinking about where things are being placed, then the memory of the last place or where it should be is retained. I did this, AGAIN, yesterday- I had moved the case for my sabre saw to a place that wasn't typical and looked high & low for it (literally- I looked upstairs, downstairs and in the garage, where it has a specific place).
But I don't freeze in place, not moving or thinking. Listening to someone is one thing, but needing to be jogged into action by someone else is another. Look at his eyes- sometimes, he looks like he's there and then, his left eye closes partially and he's gone. His mouth is open a lot more often, without speaking and it's not a natural looking position.
At our age, our minds wander but if someone has to grab him to make sure he walks to the right place (Jill, usually), come to attention or correct his body position, something is off. He bends at the waist frequently, too- that's not listening to someone, that's similar to a change in his gait which, by itself, is an indication of motor and/or balance issues. He seems to be thinner, too- not a problem by itself as long as he's physically active, but it can also mean he's doing very little physical movement, as in, muscle atrophy.
Some exercise might help him sleep, if that's actually part of his problem- physical therapists like to have patients do leg raises in all directions in order to improve balance- I would like to see his doctor prescribe this, to see if his movement & balance improve.