Doomsday
STAR: 25 Years Later, Jones Gives His Side Of Walker Trade
"I spent all night, or into the wee hours of the night, at some restaurant over in Irving... with Herschel and his agent, Peter Johnson, negotiating what to give Herschel to agree to make the trade. Herschel had the right to say no, so Herschel had to agree to make it."
My guess is that because the modern Collective Bargaining Agreement didn't exist, the wording in the contract was such that
it officially was not called a no-trade clause, but that Walker did have the right to reject a trade. Darrin Nelson, example mentioned earlier. Hershel didn't have any no trade clause. He had the leverage of refusing to report.
Then we have the added bonus of most journalists being lazy and not really doing the research but instead just repeating what they heard.
"A lot of people don’t know, or maybe just don’t talk about, the other part of the story and that was the million dollars to accept the trade." He continues, "I didn’t want to go to Minnesota. Jerry worked hard to make that happen. And he was very smart in doing that.""