I never heard of Mark until this case appeared on the news. There are such a large number of flaws in his conviction I have developed serious doubts about his case.

I have driven on those roads north of Kapiti at an average [mean] speed of 110km/hour. To achieve that average speed, I reached extremely high speeds for sustained periods of time. [I wouldn't do it again].

The difference between reaching speeds of up to 120 km/hr and average of 120 km/hr on North Island roads is massive. I suggest you try an experiment yourself. Get off a motorway and try to make a road trip averaging 90km/hr. You will soon realise that you either have to maintain 90km/hr through 50km/hr areas or else reach huge speeds on the open road to make up for all the time you spent below 90km/hr. Now imagine trying to maintain an average speed of 120 km/hr.

I have been in IT for 19 years. The computer clock time evidence is very misleading.

 I quote an earlier commentator:
"It was determined that the computer was last shut down at 10:52 pm on 29th August 2000. This was the time on the Windows 98 swap file and registry file. It was also determined that the clock was accurate by reconciling the time of computer modem calls to the Internet with Telecom call logs.

The Police theory for the murders was that Mark drove from Petone, arriving at his home around 7 pm on 29th August 2000, and adjusted the computer time to 10:52 then shut it down to make it appear that the computer was running until this time. It is alleged that he then murdered his wife and daughter and returned at high speed to his motel in Petone.

Police computer expert Maarten Kleintjes put forward methods by which the computer clock could be manipulated without leaving any evidence. He also testified that the registry backup files were out of sequence indicating "extensive manipulation" of the computer clock."

Now I would need all the detail of what Maarten Kleintjes evidence was, to critique it properly however consider this:
"It was also determined that the clock was accurate..."
At what time and day was the clock known to be accurate?
Let's suppose it was known to be accurate on day 10 and the murders occurred on day 11.
 

"He also testified that the registry backup files were out of sequence..."
There are so many ways that this can occur - it is in itself no indication of tampering. It is a common occurrence, particularly on home PCs.
What were the time and day of each of these backup files?
Were the backup files on the days in question out of sequence?
Even IF someone had changed the sequence of these files it is highly misleading to suggest that ANY change of sequence makes the clock time on the day in question invalid.

If you study these details you may find some serious doubt about this theory.