That guy is just trolling. He no more works for twitter than you or I do.
I figured you were wrong, so I searched for him on LinkedIn. Nope, nobody with that name has an account on LinkedIn.
There IS a close account for “Jackson Lees-Mulholland” who is a Plant Mechanic at Gravity Crane Services in South Hedland, Western Australia, Australia. But I doubt that is him.
How many employees of LinkedIn would NOT have an account there?