Weird.....when I was interviewed for my TS security clearance in the Army they asked me if I wanted a lawyer present and had me swear to tell the truth, the whole truth, and nothing but the truth. Michael was not informed he could have a lawyer present nor was he informed that he was under investigation. And because he was under investigation they needed to inform him of his rights.
Flynn was NOT the subject or target of an investigation, or the FBI would have informed him, and informed him of a right to have a lawyer.
Flynn was NOT under investigation. They were questioning Flynn to verify what Flynn told Pence.
And as you said during your TS interview (which Flynn went through half a dozen times) they need not remind him "one more time"