Ehrlichman wrote two letters to Trudeau that are preserved in Trudeau’s archives at Yale. This letters from May 18, 1973, on White House letterhead asks for the original of a previous strip (which one is unclear). The handwritten note says:
“I hear my resignation fouled up your following series – Sorry – Next time (!) let me know whaty ou’re planning and I’ll try to cooperate – JE.” He was convicted 19 months later.
Ehrlichman in his office: https://www.gettyimages.ca/detail/news-photo/former-white-house-special-assistant-on-domestic-affairs-news-photo/615291646