A Delaware court sided with Tesla CEO Elon Musk in a bitter legal battle over whether he acted against the best interest of other shareholders when he steered the electric car maker into a $2.6 billion acquisition of a solar panel maker founded by two of his cousins.

CEO Elon Musk pushed back again Tuesday against a lawsuit that blames him for engineering Tesla’s 2016 acquisition of a financially precarious company called SolarCity that was marred by conflicts of interest and never generated the profits Musk insisted it would.

In the runup to electric car maker Tesla Inc.’s 2016 acquisition of SolarCity, Elon Musk called the combination a “no brainer,” a one-stop shop for electric cars and the solar panels to recharge them.

Tesla founder Elon Musk took to a witness stand Monday to defend his company’s 2016 acquisition of a troubled company called SolarCity against a shareholder lawsuit that claims he’s to blame for a deal that was rife with conflicts of interest and never delivered the profits he had promised.

"Please allow us to send you a small gift of short shorts to help you through this difficult time," Musk wrote, invoking a jab he has used with Tesla short sellers, or investors who bet against a company's stock performance. Musk, who is known for publicly sparring with Tesla naysayers, previously sent Einhorn a box containing several pairs of short shorts, to which Einhorn responded with a sarcastic thank you via Twitter. Einhorn's Greenlight Capital has long had a large short position in Tesla, meaning it loses money when Tesla's stock performs well. When Tesla posted a surprise profit on October 23, sending its share price up 30%, Greenlight took a significant hit. One lawsuit filed by Tesla shareholders alleges Musk engineered the purchase of SolarCity, in which he was the majority shareholder, as a a bailout of the troubled solar panel company.

One is challenging the terms of a compensation package that could end up paying him stock worth more than $50 billion over ten years. That could be bad news for Musk and Tesla, potentially disrupting the ambitious goals he has set for his various companies. Musk was chairman and the largest shareholder of SolarCity, a company that was run by his cousins at the time of the purchase. The lawsuit challenges a compensation package that Musk was granted last year by Tesla's board. Shareholders approved the compensation package in March 2018.