Oscar Piastri described Alpine's attempts to announce him in their 2023 driver line-up as "very upsetting" after motorsport's governing body ruled he could sign for McLaren.
Alpine and McLaren were locked in a battle for the services of the 21-year-old, who was a member of Alpine's junior programme and held reserve status with the team this season.
Both teams were in need of a new driver ahead of the 2023 campaign after Fernando Alonso announced he would be leaving Alpine for Aston Martin, while McLaren agreed an early termination of Daniel Ricciardo's deal.
In August, Alpine announced Piastri as a new driver for next year, only for the Australian to deny he had agreed to take a seat with the team.
Friday's ruling by the FIA's contract recognition board (CRB) left Piastri free to partner Lando Norris for McLaren next year, and he has hit out at Alpine's decision to make what he feels was a "false" announcement regarding his future.
"My decision was made well in advance [of Alonso's departure], which made Alpine's announcement probably even more confusing and upsetting because we had told the team that I wasn't going to continue," Piastri told Formula One's website.
"It was quite upsetting as the announcement was false and it also denied me the opportunity to properly say goodbye to everyone.
"I had been with the team for a bit over two and a half years now, and for the rest of the team to find out I was leaving in that manner was very upsetting.
"I still haven't had the opportunity to say goodbye and it's something I want to do, to show my gratitude to all the men and women at Enstone."
Piastri moved to defend his social media intervention following Alpine's announcement, claiming his decision to speak out was a necessary measure.
"It [the announcement] was done publicly in front of some members of the team who were oblivious to the situation and I didn't want to cause a scene in front of them. It was the biggest moment of my career and probably my life up to now," he said.
"To have that falsely announced was something my management and I felt we had to correct and there was also potential legal implications if we didn't deny the announcement.
"It was not intended to be pointed or in any way anything more than factual. The last line was quite a strong one, but with the CRB ruling, it shows it was purely a fact."
Regarding his decision to seek an exit from Alpine, Piastri pointed to what he described as a "breakdown in trust" between himself and the team's hierarchy.
"To be completely honest, there was a lack of clarity around my future at the team at Alpine," he said. "They publicly stated they wished to continue with Fernando for at least one or two more years. I respect that.
"But after spending the year out, my hopes were firmly set on an Alpine seat and the lack of clarity and, similarly to Fernando, a bit of a strange feeling in negotiations… it didn't feel like it was the right decision for me [to stay].
"The lack of clarity around my future, and ultimately a breakdown in trust, I felt the very attractive offer of McLaren, and the positive dealings with them thus far were all reasons why I felt McLaren was where I was best off for the future."