He took the urine test on Dec 7 with his personal doctor, and not at one of the approved facilities. The NSAC rejected this test, and he didn't take a proper approved urine screening until Dec. 14, which ended up being like 3 days shy of a month.
I also think the NSAC did themselves and Overeem a disservice but not asking Overeem to provide proof of when he purchased the plane ticket. That could have ended all doubt as far as the accusations of bolting to Holland to avoid or delay the test, under the pretense of visiting his mother. But even if he's off the hook for that, he still showed a casual disregard for the process and the need for urgency of a random screening.
My main gripe is due to his lack of communication and urgency, whether intentional or not, he skirted the test for almost 30 days, completely negating the idea of a random test. And to be honest, personally I don't really give a fuck if he's using or not (because I think the majority of these high level fighters use anyway), but the bigger picture here is the NSAC granting a license for obvious business and personal reasons. That type of inconsistency blows the credibility of the testing out of the water, so why even test to begin with? It's a dog & pony show. There is no way you can license Overeem here with and retain any shred of credibility based on the events, and there is no shot an undercard fighter or non Zuffa fighter would have been approved under these shady circumstances (in fact, no other fighter who missed the deadline has ever been approved by the NSAC).
My opinion, for whatever that's worth, is that Overeem intentionally skirted the urine test for as long as he reasonably could. I think he lacks credibility due to the large gaps of time between steps in the process. And the NSAC comes off even worse for allowing it. One of the smartest things Zuffa ever did was hire Marc Ratner.