The blood test is just an indicative that Zummock´s story is bullshit. Of course she was retested but there would be no reason to test her with a short time detection span test after she wasn´t in Nick´s custody anymore and after going through a perfectly accurate one (hair follicle).
In the end it'll take actual documents through a less laughable source to ever unironically believe it, but just to play devil's advocate for a moment, one possible solution to the problem of blood tests' narrow detection window could be that sometime within 24 hours of the arrest on May 23rd, one or more of the kids was brought straight to medical testing and care that happened to include blood draws ostensibly unrelated to drug testing, and some unused portion of a blood sample was properly preserved just in case it might be needed later. Then, when Nick and the Barneswalker surprisingly fought the CHIPS case on every front to the point that
the state had to tee up a slate of 6 lab witnesses and Nick had to
hire a lone "expert" witness to counter them and bury the state with eleventh-hour
onerous discovery demands pertinent to challenging the hair test, perhaps at some point someone at the county got the idea to simply grab one of the weeks-old or even months-old blood samples out of the freezer and submit it to drug testing to corroborate the hair test that was clearly about to be under heavy attack in the
July 23rd CHIPS trial that had to be
postponed to August 27th to give the state more time to respond to said discovery demands.
But how long could such a blood sample be usable in that way, you ask? Naturally the self-evident need for that answer in death investigations' tox screens nationwide will have brought about reliable studies long ago, and although it depends on the storage temperature as well as whether appropriate measures were taken to reduce alkalinity and inhibit cholinesterase reactions, in theory even a poorly preserved May 23rd or May 24th blood sample could have reliably corroborated the hair test well into June, and a properly preserved May 23rd or May 24th blood sample could have reliably corroborated the hair test as late as August:
Kiszka, M. & Buszewicz, Grzegorz & Ma̧dro, R.. (2001). Stability of cocaine in blood and in other tissues. Z Zagadnien Nauk Sadowych. 45. 16-35.
That hypothetical scenario of testing a preserved sample would at least plausibly explain why the publicly known CHIPS documents are completely devoid of any mention of a blood test whatsoever, because the actual testing and test results might not have entered the fray until well after the last publicly known occasion for findings of fact on June 6th or potentially even well after the CHIPS file was sealed in late July or early August. It would also explain Nick's chats' very odd obsession with repeatedly quoting "multiple times" as the only thing to deny while entirely evading the more pressing question of whether multiple tests occurred
regardless of their timing: in his diseased mind so addicted to dopamine rushes from watching weasel-worded gaslighting take effect like it's a vidya game on his way to the high score, multiple tests including a June, July, or August test of a May 23rd or May 24th blood sample aren't technically "multiple times" because the blood sample itself was technically drawn at the same "time" as the hair sample. Checkmate, prudes!
What could his next Quora cope even be if anything like the above is what happened?