You pretty much have everything backwards. Musk has requested for almost no contingencies, even opting out of due diligence. The only contingency is Twitter not committing fraud in their filings with the SEC.

Their filing on active users are extremely narrow in their claims - the only way they could realistically be shown to be fraudulent is by discovering in internal emails that they were crafted to deceive; otherwise, they are very specifically saying that the 5% number they give is only an estimate and that it involves a judgment call in how it was decided. So if you find some way of calculating bots and come up with 20%, that still doesn't mean they misrepresented the numbers: they never claimed 5% is a precise number, just their judgment based on some sampling they did.

Futhermore, even if the number is found to be a lie, that still wouldn't mean they materially lied to the SEC - you still have to then prove that this impacted their revenue projections significantly (apparently the standard is "at least by 40%"), which comes with even bigger burdens of proof. You would have to show that Twitter's clients (advertisers, mostly) were relying on the reported numbers to decide if they were getting a good deal, and that they would significantly change the price/number of ads on Twitter based on this difference. This in itself is unlikely, as these companies have their own metrics for judging whether an ad was effective, and in the many years Twitter's official bot estimates have stayed the same, they would have had time to notice if their revenue from advertising on Twitter was worth it.

Even worse, Musk has been claiming that Twitter's reported bot numbers are much lower than reality for many years before he made the offer to buy Twitter, so his belief can't have materially impacted his willingness to buy. He even publically talked about cleaning up Twitter of it's bot problems as a specific target after the acquisition. These public statements will again significantly affect any claim that Musk makes that any new information he finds on the number of Twitter bots would have impacted his decision to sign the contract if it had been disclosed before hand.

Finally, note that the information he asked Twitter to provide (access to tweets) has almost nothing to do with the discussion about revenue, as Twitter's revenue comes from users reading tweets, not writing them. The 5% number is about users who request the Twitter feed and receive ads, but are in fact bots and thus can't buy products. This is completely uncorrelated to the number of bots and other fake accounts who might be posting tweets, as there are no ads in the tweet posting pages.

In short, if Musk analyzes the data he received now from Twitter and discovers that 100% of all tweets are actually made by bots, it will not make one iota of a difference to his obligation of paying the $44B he singed on. Twitter makes no claims to the SEC about the number of real VS fake users posting tweets, and this number has no direct impact on revenue. The only claims by Twitter are that by their own internal process and judgment, up to 5% of monetizable daily users are bots, and this can only refer to users reading tweets, not posting them, based on how Twitter works.