Mr Stott believed the Carterton balloon crash, which killed 11 people in January 2012 had taken priority over his son's crash.
Mr Stott's son-in-law, Corey O'Leary, who has been representing the Stott family, said he could see the issue from both sides and "to be fair" to TAIC, it had had other crashes to deal with.
"Obviously, the hot air [balloon] was a commercial [flight] with paying tourists. Obviously, that takes a bit of priority, which I can fully understand.
"It's one of those things that takes time.
"At the end of the day, they have got to be thorough and correct."
TAIC general manager communications and investigation support Peter Northcote, of Wellington, told the ODT this week the commission regretted the delay.
Its aim was to complete inquiries within one or two years, "depending on complexity and availability of staff and case prioritisation", he said.
The reasons for the delay included the commission having two investigators, rather than three, during much of the time since the crash.
It had to prioritise cases in the same period, including aviation crashes at Fox Glacier, Feilding, and Carterton.
A report into flying training safety was also given priority as were several commercial airline "incidents and accidents", he said.
"We do appreciate that waiting for answers can be hard on those affected, and we have been keeping family representatives and other parties concerned updated ... throughout."
The commission has yet to consider submissions on the draft report and decide if more work needs to be done.
"Assuming this is straightforward, then a final report is expected to be published in March 2014."
