Whether the individual acquired non-UK residency and ordinary residency from the day following departure in June 2005 is unclear.
The reason is that the initial contract of employment terminated in Sept 2006 before the individual had spent one complete tax year abroad.
What date di it terminate and from what date did the new contract commence?
Were the two contracts with the same employer or "group" or with unrelated employers?
You also state:
the individual visited the UK a lot less than 90 days per tax year, with the lion's share of the time being related to employment rather than personal.
Are you saying he worked whilst back in the UK; were these incidental duties; how many days in each tax year were involved?