I don't think either sets of advice have actually hit the spot - meaning those from your current and former accountants. To expand a little on AG's contribution:
It's sad that it's so difficult for even qualified accountants to interpret the rules and for them to get it so wrong.
We might need to know Joe's domicile status to be absolutely certain but, to the extent that Joe's duties are performed outside of the UK and he is not resident in the UK, then he should NOT be taxable in the UK (although he may be taxable in the country/ies in which he is resident). Things can be more complicated where he is also a director of the company because at least some of his duties may perforce be performed in the UK. Careful and tailored guidance would be appropriate in this regard.
I'm sure he'd be classed as domiciled, he has family ties and bank accounts in the UK.
He's tax resident in Dubai where there's no income tax.
None of his duties are or need to be performed in the UK.
Likewise in relation to dividends paid by the UK company of which Joe is a shareholder. There is a question of whether the company is distributing profits deemed to have arisen prior to a period of temporary non-residence, or dividends paying out profits that have arisen while TEMPORARILY non-resident.
There are currently no profits in the company to be taken out. Profit will have only been generated after having attained non-resident status.
There is also the matter of the Double Taxation Agreement between the UK and the country/ies in which Joe is now resident.
No such issue to worry about here I wouldn't think since as mentioned, it's Dubai and there's no income tax. Not too sure about Corp tax but that's not that important at the moment.
Thanks for your all for your advice so far. I've reached out to some accountants and I'll update with anymore info I get. I would appreciate more advice on this though so if anyone else has any input, I'd really appreciate it.