Elon Musk was permitted to revise his complaint against Twitter on Wednesday by a US judge, but the lawsuit against Twitter over the collapse of the businessman's acquisition proposal was not postponed.
In a split decision, Kathaleen McCormick, the chancellor of the Delaware court, said Musk could add indiscretions made in August by a former security chief for Twitter.
She rejected his request to delay the lawsuit, claiming that doing so "would risk further harm to Twitter that is too great to justify."
Musk has been locked in a bitter legal battle with Twitter since announcing in July that he was pulling the plug on his $44 billion company purchase following a complex, volatile, months-long courtship.
Musk has said he canceled the deal because Twitter misled him concerning the number of bot accounts on its platform, allegations rejected by the company.
Revelations from Twitter's former security chief Peiter Zatko criticising Twitter's security practises first became public in August following a report in the Washington Post.
In a hearing Tuesday, attorneys for Musk sought to amend his appeal and be granted additional time for document discovery to investigate Zatko's assertions.
Twitter attorneys contended Musk's proposal was another delay tactic to sabotage the purchase.
McCormick said Musk had overcome the relatively low legal threshold to modify his lawsuit against Twitter, adding that she was "reticent" to judge on the merits of Musk's allegations "until they have been properly litigated."
But she said Musk's side would be allowed "only cumulative discovery" to follow up on the new accusations made in light of the requirement for a speedy resolution of the case.
"The longer the halt until trial, the greater the likelihood of irreparable harm to Twitter," McCormick said, noting the company has experienced severe staff turnover. In contrast, it "has been compelled for months to handle under the constraints of a disproved merger agreement."
The five-day trial is due to go forward, scheduled to begin on October 17 in the Delaware court.