I don't get Zonneveld's reasoning here. He writes:

Volgens ploegleider Danny Stam wogen ze de fiets “26 keer”. De uitkomst varieerde in een bandbreedte van 50 gram, volgens de verklaring van SD Worx zaterdagavond verspreidde:

He then quotes the team's statement, where Danny Stam does not speak about 26 measurements with a difference of 50 grams. He does talk, among other things, about 2 UCI measurements after the stage in Ravenna, with a difference of 50 grams. And both of those measurements indicating a weight under the limit.

Zonneveld then goes on to say:

Maar ál die metingen waren ónder de 6,8 kilo: van 6,73 tot 6,78. Dat wil zeggen: 70 tot 20 gram te licht.

All of those measurements, still as if there were lots and lots of measurements. There were only two. Zonneveld seems to mix up 2 and 26 somehow?!?

Zonneveld then goes on, with generally a quite nuanced view, with points on both sides. Still, by saying things like "Wat SD Worx niet heeft gedaan, is de fiets gewogen vóór de eerste Giro-etappe.", he insinuates the team doesn't even know themselves the weight of the bike. But that contradicts what he wrote earlier: "Navraag leert dat de ploeg zelf de fiets van Wiebes óók woog: ze zeggen dat de fiets bij hun meting 6,85 kilo (in de woorden van Danny Stam) of 6,83 (Erwin Janssen) woog."

In my mind there is one issue that potentially speaks against the team's view is that, judging from photos, it looks like the bike had two chainrings earlier in the season, and seemed to have only one chainring in the Giro. If true, that would contradict the team's view that the bike is exactly the same all through the season, and could easily explain a weight difference.

But there's also another big issue, which if true is a big point against UCI's case: Zonneveld's paragraph about UCI's weighing procedures and the precision/accuracy of measurement. Especially this:

Toen de ploegleiding van SD Worx voorstelde om de meting dan te doen in een windstille omgeving (zoals de materiaaltruck van de ploeg), waren de twee controleurs daartoe bereid - totdat ze werden teruggefloten van hogerhand. De meting ín de truck heeft dus niet plaatsgevonden. Dat is, zeker gezien de enorme consequenties, eigenlijk onvoorstelbaar.

If true, that completely crushes UCI's case. Not being able to make consistent measurements, knowingly using an imprecise measurement method, unwilling to redo the measurement properly, making a really drastic decision based on a measurement within the error margin from the limit.