In my novel, twenty years from now, a physicist/computer scientist has created a machine version of himself, an artificial general intelligence that integrates the physicist's personality, memory and consciousness. This concept doesn't sit well with computer scientists. One objection is that an AGI is almost a blank slate, a learning machine (perhaps an artificial neural network) that doesn't have lines of programming. I'm not writing hard science-fiction, but I want the concept to approach scientific possibility.
If you're avoiding the hard science, then I'd focus on the dimensions of the AGI, as in how would it be different to the human intelligence it's integrating with, and how those two intelligences would be out of alignment.
As an example, consider the perceptual differences between them, and how the AGI would be coming to terms with having direct access to the physical world, emotional states, and perhaps basal functions.
But then there's the option to explore what the human would have access to and experience, such as enhanced logical thinking, and problem solving on a massive scale.
Do What Feels Right:
It's the future. Scientists haven't made real AI, so they can't object to your version of it. Just because they think it has to be one way doesn't mean it will. Intelligence is a murky concept. You can do what you want. Read any of a number of science fiction books with AI and they all use colorful reasoning that's short on detail but feels right. It reminds me of my favorite AI joke about humans. The AI asked the human how he ever thought the crazy hacking scheme would work. The human said it felt logical.
The core problem with digitizing the information on a human brain is that for all the advancements in computer processing power, the human brain is still better. It's estimated that the human brain could store 2.5 million gigabytes of digital information (or the equivelent of digital recording a television station every day for the next 300 years). By comparison, the IRS has a storage capacity 150,00 gigabytes, and yahoo's 2.0 petrabyte data warehouse is only 80% capacity of a human brain. The amount of data space alone for something like this is insanely massive an while computer's were predicted to double memory every 2 years and has largely kept pace with that (Moore's law) we may be approaching the upper limits of that from a physical standpoint, as of the 2020s (that is, to keep pace, we are appoaching the miniturization of transistors to atomic sizes... it's impossible to go smaller than this).
That said, there are some reasonably life like programs that exist out there that occasionally pass the Turing Test (i.e. sit at a computer and have a conversation with a person in another room who you cannot see. If you cannot tell that the person is in fact a computer, the computer passes the Turing Test), but these are hardly digitized human brains, but rather text (or speech) parsing programs that have very good predictive models for returning expected responses to comunicated stimuli... they aren't going to learn.
It's probably unlikely that we'll be able to create an intelligence on par with a human in 20 years. (Musk et al be damned! :)
What we have today is the equivalent of a digital parrot... or in fact, that may be condescending to parrots. A digital dog that can fetch and sit... it just fetches words and images and we think it's so clever for doing that...
But as @DWKraus says, we don't know what the future will hold.
I first misread your question as the scientist having created a digital clone of himself (or has he?) This could then involve some scanning and cloning of the brain into digital form (think OpenWorm but with brain scanning + digital cloning).
Extrapolate 20 years from that... OpenMouse? OpenDollyTheSheep?
If he used the technology on a human brain he'd be way past the fringe... and that cloning may have been more or less successful. (And a glitchy AI might be an easier sell.)
Some of my favorite AI:s (HAL for instance) aren't as good as they seem to be from the start. And a malfunctioning AI can be used to make a nice comment on society, psychology, and/or technology (it's after all what some of the best SciFi do...)
And it could also be used for comical effect, if that's what you're after (or hey, whatever story you're writing, comical relief can always have a place...)
One such glitch could be that the AI takes things too literally:
Scientist: We're gonna blow their minds!
AI: I'll get the C4!
Has low or zero ability to navigate social situations... Understanding instructions but requiring them to be precise or there will be unexpected results. etc. etc.
You could blame the AI for being as annoying as a Smartphone... :)
And then you might add fixes for the issues. Reboots, reindexing, resets, or something similar.
However, check out the great masters in SciFi. I'm willing to bet very few of them explain things.
You could just say, it's an AI and it has the scientist's personality, memory, and consciousness. Something huge will happen in AI tomorrow! Period!