He had been advised that a negative B-sample would be a rarity in the extreme and yet he returned one - heightening the probability that a mistake was made by the WADA-accredited laboratory Sports Medicine Research and Testing Laboratory (SMRTL) in Salt Lake City where his original sample was tested.
New Zealand Rugby Players' Association boss Rob Nichol said inquiries will continue to determine why the A-sample did fail.
"This is a matter that SMRTL is investigating and we look forward to their feedback," said Nichol. "Working with Patrick through the process, we always felt confident that he would be cleared," said Nichol.
"To be honest, there is an element of frustration, given the initial result and publicity, but at least people now know Patrick did nothing wrong. This result also reinforces the importance of the regulations and strict confidentiality obligations regarding players and their rights. Patrick was unfairly labelled as a result of the premature publicity of this matter. We trust that everyone now has a greater level of understanding in this regard."
Tuipulotu hasn't been able to train with the Blues squad since his suspension but is understood to have trained on his own and is in good physical shape. He'll work through with Blues and All Blacks conditioning staff when he should return to play but, despite the uncertainty over the summer, it's probable he'll be available from the beginning of March if not sooner.
And for the Blues, the relief will be considerable. They have a backline that has incredible potential but without Tuipulotu, they may have struggled to win the ball, or deliver the sort of grunt and graft required to compete with the best teams.
His return to the boiler room will give the Blues presence in the collisions and also a dynamic ball-carrying force.