This seems to be completely implausible. Whatever email is tied to this account would have been instantly notified about a "suspicious login".
There is absolutely no evidence in the article (not even links or screenshots of his tweet reaching out to the White House).
Furthermore I can't believe Trump's account is even going through regular authentication mechanisms. It should be trivial to restrict access to an account to certain address ranges of a government VPN.
That is what likely happened:
"A day after he gained access, Gevers noticed that two-step verification had been activated on Trump’s account. Two days later, the Secret Service got in touch. According to De Volkskrant, they thanked him for bringing the security problem to their attention."
There's been repeated claims that Trump has - up until recently - used personal Android and iPhone devices to make calls and tweet. Not clear if that's true or not.
There is absolutely no evidence in the article (not even links or screenshots of his tweet reaching out to the White House).
Furthermore I can't believe Trump's account is even going through regular authentication mechanisms. It should be trivial to restrict access to an account to certain address ranges of a government VPN.