Dominion is suing him...
This is my understanding on the matter (I'm no lawyer, but I've seen a bit of legal proceedings in my time).
If he releases the evidence he collected personally, which instigated the suit, he is basically giving up the ability to use the evidence in discovery as a defense for his statements.
If you release evidence publicly, a judge can rule it inadmissible if it has too much public attention. It could sour the ability to put together an unbiased case.
If that happens, other judges would also be able to strike down the same data for the same reasons, based on precedent.
That might be the reason he isn't putting them out there. Dominion is just buying time in court to prevent the data coming out now.
You might say "but he already has publicized his findings."
True, but at this point it's just hear-say. Actually handing out the dirty laundry of Dominion would 100% make it impossible to put together an unbiased case.
Remember the ultimate reason the court system gives when you ask them "but, why do it that way?"
"F#CK YOU, THAT'S WHY" - Every judge, ever.
It sucks, but that's just how crooked the court system is.
Edit: I'm dumb, it's a civil case, so no juries. Still, it isn't good form, as it tells the judge you're not gonna play nice. I made some corrections. jury->case. Thanks to u/amarQ144/ for pointing it out before I make us look too foolish.
None of those really seem applicable here. 403 covers evidence that is in itself prejudicial or “needlessly cumulative” in the sense that the litigant is trying to swamp the court with documents. Rule 37 covers litigants who fail to participate in good faith at the discovery stage. Barring some weird corner case—though I can’t think of one—neither would permit the exclusion of otherwise material evidence just on the grounds that one of the parties made it public in advance of litigation. Rule 26(a) gives a party an opportunity to ask to delay compelled discovery; it doesn’t mean nobody can publish any information related to the case until the court says so.