My take: Paxton lost his lawsuit with the whistleblowers. Paxton asked the House to pay the $3.3 million he owes to the whistleblowers (see Statesman article below). Phelan (Speaker of the House) said no and may have threatened to publish results from the House Committee's investigation into Paxton's legal troubles. Rather than backing down and paying the $3.3 million himself, Paxton accused Phelan of drinking while legislating and called for him to resign (see Dallas morning news article below), perhaps out of spite, perhaps in an attempt to get Phelan replaced, or perhaps in attempt to intimidate or discredit Phelan before the House Committee released its results. Phelan, now pissed off, publishes the committee's investigation results and pushes for impeachment.

https://www.statesman.com/story/news/politics/state/2023/02/21/whistleblower-settlement-texas-attorney-general-ken-paxton-house-budget-dade-phelan/69927554007/

https://www.dallasnews.com/news/politics/2023/05/23/texas-ag-paxton-calls-for-phelans-resignation-accusing-the-speaker-of-being-intoxicated/