Reagrdless of what turns out to be odd about the Regeneration on-screen it seems to be a bit odd off-screen as well. Here's a quote from Capaldi talking about it in USA Today.
"I didn't realise it was my last series until about halfway through it. I was just delighted to be carrying on being the Doctor."
That doesn't sound like someone who'd been planning on going anywhere.
"I didn't realise it was my last series until about halfway through it. I was just delighted to be carrying on being the Doctor."
That doesn't sound like someone who'd been planning on going anywhere.