Pakenham lasted barely a few days in the community before Corrections said his accommodation was "unsuitable" and put him back in custody.
He is now awaiting a recall hearing in front of the parole board.
Mr Tinsley, one of the lead investigators on the case, says while the recall shows police are actively monitoring his parole conditions, Pakenham clearly still hadn't lost what he described as his ability to "make things up".
"You would have to question the sincerity of how he presents [to parole board]. Obviously they are considering that, it would be frightening if they weren't, but given the fact that he seems to have flip-flopped from guilty to not guilty to no knowledge or involvement at all just to suit himself and pave his way to get an easier ride so to speak, it's really questionable.
"All that points to him being a really complex fulla, but can you have any faith in anything he says? You've got to question that."
In its 2014 parole decision, a psychologist noted Pakenham was "prone to changing his accounts of events" in regards to Ms Niethe's death.
By 2015, it described him as having traits of "superficiality, grandiosity, deceitfulness and lack of remorse and empathy".
"He is said to be at moderate risk of violent offending against particularly adult females within two years of his release," the report writer wrote.
He was also described as giving "inconclusive and contrary answers".
In its latest decision - which led to his release - comments were of a similar vein.
"Mr Pakenham's case is an unusual one in respect of the manslaughter conviction ... but suffice to say that in the Board's view Mr Pakenham's decision to plead guilty to manslaughter to avoid a murder conviction and then subsequently through his sentence to deny even the manslaughter suggests a person who is dishonest."
The Herald has previously reported Pakenham has a lengthy criminal record, resulting in stints in jail, dating back to 1978 which includes assault, threatening to kill and possession of a large amount of methamphetamine.
Mr Tinsley says he now wonders "what is he capable of?"
He doesn't believe it will be the last the public hear of Mark Pakenham.
As for whether Pakenham should have been paroled to his accommodation in the first place, Mr Tinsley was reluctant to criticise the Corrections Department but said "they do need to be answerable".
"That's a logical question and they should answer it for the public ... if they're putting this person back in the community, the community have a right to know that they are safe and what's going on."
Meanwhile, a New Zealand Parole Board spokesman says accommodation for release is assessed by Corrections and specified by the Board in the release conditions.
"Both the Board and the Department of Corrections are focussed on community safety and this is crucial in the assessment."
The Herald is waiting for a response from the Department.