Actually, the author kept writing "clever-but-contrived escapes" and it was the editor, John Campbell, who wanted to go against the grain:

I learned how strong the hand of the editor can be in shaping a story. John told me he had three times! sent "Cold Equations" back to Godwin, before he got the version he wanted. In the first two re-writes, Godwin kept coming up with ingenious ways to save the girl! Since the strength of this deservedly classic story lies in the fact the life of one young woman must be sacrificed to save the lives of many, it simply wouldn't have the same impact if she had lived.

John wasn't trying to take credit for having shaped one of the masterpieces in the SF field. His attitude and words clearly indicated he simply felt it was the responsibility of an editor to improve on any given story, where possible -- and he had done that.

http://www.challzine.net/23/23fivedays.html