Alexander Carter-Silk, the lawyer at the centre of a media storm over a LinkedIn message, has left his post at U.S. firm Brown Rudnick to join listed outfit Keystone Law.

Carter-Silk, formerly the European head of IP at Brown Rudnick, came under intense media scrutiny in 2015 when female barrister Charlotte Proudman, then 27, accused him of “unacceptable and mysogynistic behaviour”, after she publicised a message exchange that showed he complimented her “stunning” profile picture.

The story sparked a widespread debate over unsolicited compliments on social media and in the workplace.

At the time of the incident, Brown Rudnick acknowledged awareness of the comments and  apologised for any offence caused. The Telegraph reported that Carter-Silk, 57 at the time, said in a message to Proudman: “I sincerely regret my remarks have offended you.”

Carter-Silk had been head of IP at Brown Rudnick since 2014. He had previously headed up intellectual property teams at legacy firms Speechly Bircham, from 2006 to 2014, and Manches, from 2003 to 2006.

In a screenshot of the exchange – which Proudman publicised via her now-deleted Twitter account – Carter-Silk wrote: “Charlotte, delighted to connect, I appreciate that this is probably horrendously politically incorrect but that is a stunning picture!!!

A tweet from Proudman's now-deleted account.

“You definitely win the prize for the best LinkedIn picture I have ever seen. Always interest [sic] to understant [sic] people's skills and how we might work together.”

Proudman replied: “Unacceptable and misogynistic behaviour. Think twice before sending another woman (half your age) such a sexist message.”

Carter-Silk told Legal Week: “I greatly enjoyed my five years at Brown Rudnick working with amazing people on cutting edge intellectual property law, particularly disruptive technology issues.

“I am excited to have moved to Keystone Law to expand on that work. I do not wish to re-open a five-year old debate about one comment simply because I have moved firms.”

Responding to a request for comment on the incident, Keystone CEO James Knight said in a statement to Legal Week: “We are delighted to welcome Alexander to the firm and look forward to working with him.”

Brown Rudnick did not respond immediately to requests for comment.