[ojnabieoot]

The problem is that the election was clearly unfair and there was a widespread sense that the people voting in it thought it was unfair. A 70-30 vote in an election where you know the authorities are watching means absolutely nothing.

As for this:

> The evidence seems to be based on the word of a single employee. If that's enough evidence to overturn an election, it will be hard to have one that isn't overturned.

You are reading this very myopically, ignoring crucial context with a sliver of the article (and not being helped by some weak writing). The snippet should be read as this:

> Myers’ recommendation centers on the mailbox [which was unquestionably on Amazon’s headquarters and which Amazon management unquestionably pressured employees to use for voting], according to one of the people familiar with it. During the NLRB hearing, an employee said Amazon security guards used keys to open the mailbox, testimony that former NLRB chair Wilma Liebman said could be reason enough to overturn the result.

So there was plenty of direct evidence suggesting improper behavior, which not even Amazon contested. That was not enough to overturn the result. But just the one piece of deeply serious eyewitness testimony on top of the documentary evidence would be enough. And of course there was far more evidence than just that one employee: Liebman’s comments are obviously a rhetorical device used to illustrate the severity of Amazon’s transgressions and not a literal description of the merits of the case.