Was Eve's Father faking dementia?

I doubt the whole dementia was faked. It just would not have made sense that after he receives the phone call he goes instantly berserk on his whole past life and starts off into a bigger lie than anything before.
But the moment in the finale you mention looks a lot like he can remember but takes the easy way out, avoiding taking the responsibility for it, knowing that soon he would not be able to remember anything of it anyway. There is this knowing expression on his face, just a hint more than that blank stare before.

I came away wondering too. Especially after the close up on Stone's face right at the end, before he launched again into a dementia type question to Eve.

One thing that might be key (I can't recall) is to watch again the episode in which Eve and Stone first have a conversation about his future and health (they don't mention dementia at that point) and what's going to happen to him etc.

It's a vague conversation about his condition or situation. But later appears to have been about the ensuing dementia.

If that convo took place long before Gettrick confronted him for help, then the dementia might be real. If only because they were speaking of his condition and future long before.

But I just cannot recall without watching again where that convo took place with regard to the entire time line.

Yes, that's exactly what I thought. In that final scene with Eve I was sure I glimpsed an expression of smug triumph flickering in his eyes. But it was left beautifully ambiguous.

The writers of the show have confirmed he did have Alzheimer's but how much he remembers at any given point is debateable.

Roger Allam is such a consummate actor of actors, it's hard to imagine that tiny flicker of triumph or smugness we saw as quick as a blink on his face meant nothing in that close up of him at the end.

It still might have been directed as "do something micro to give a hint, Roger, but not all the way," or something like that. All part of whatever the script said or how it was directed with purpose.

It's good the writers confirmed he has dementia; but the question for viewers is...to what extent has it progressed? And is he exaggerating it on purpose as needed, having retained enough to know he needs to do that right NOW to shut down questions from people.

One thing that also made me think he was exaggerating was the way Roger Allam acted the more vociferous scenes when he was yelling or reacting verbally.

There was a kind of just TINY TINY over the top nature to what he was saying. It's like Roger carefully infused his quick rants with a kind of false tone.

I listened to a few of them again to see if it was there--and I heard it. A hint of a false expression that hints at him going for it in some of the rants when he shuts down questioning.

Subtle? Sure. But in the hands of somebody like Allam, totally doable in the most subtle of ways. Maybe not easy to catch on the first viewing, but I saw it more clearly on second viewing.

But I reran that last Stone scene four times and saw the same flicker/gleam every time! haha

"THE FALL" SPOILERS SERIES 3:

It reminded me of a few scenes with Paul Spector in "The Fall." Tight close ups, right after it appeared Paul had totally gotten away with his "amnesia" then there it was...the evil eye flicker, the smug satisfaction just the tiniest of muscle in the check jerking to indicate he's trying to keep his face in control. And I guess the jury is still out on Spector's Amnesia, too!

So perhaps these scenes are purposefully ambiguous. Guess we have to wait for writers to fill us in later in interviews! haha