"It's taken a bit of the pleasure out of what's happened, what we've achieved, for me anyway", he said, adding that it had upset his ex-wife and daughter back in Britain.
Prior to their rescue, famous entrepeneur Elon Musk arrived at the scene, offering to help, with a submarine made of rocket parts.
"Your behavior is fueling an unhelpful perception of your leadership -- thin-skinned and short-tempered", Munster wrote in the letter posted "on behalf of investors who believe in you and your mission".
He has also had a contentious relationship with Wall Street analysts.
"He can stick his submarine where it hurts". After the apology, Unsworth told Reuters that he was aware of Musk taking back the slur, but would not comment on if he is still considering a defamation lawsuit.
Unsworth had called Musk's actions a "PR stunt".
"Bet ya a signed dollar it's true", he later said about the accusation. Over the weekend, for instance, Musk devoted several tweets to clarify his political stance and donations.
He also said that he would like to see "peace, quiet and execution" at the electric vehicle company. "It would be good to just concentrate on the core task".
Musk had deleted his tweet earlier but apologized for his comment on Twitter on Tuesday night. While controversy around his Twitter use may have negative effects in the short run, it creates a larger audience for when Musk promotes Tesla's products.
Elon Musk even followed insults with tweets but they were eventually taken down. Tesla shareholders joined together to demand Musk to aplogize.