Valada (Wein's widow) says Wein remained consistent in his account of the character’s creation since the beginning. While acknowledging that Thomas had assigned him to introduce a Canadian character named Wolverine in The Incredible Hulk, which Wein was writing, Wein said he did all the original research that shaped Wolverine’s powers and personality. Wein, who studied art in college, claimed he even contributed to John Romita’s character design.

This last point is disputed by Herb Trimpe, the artist who drew the first Wolverine stories, who died in 2015. In an interview that took place in 2012, Trimpe said:

“I was in the office a good part of the time and I was there when John [Romita] was working on the model for the character. The way it worked was Roy Thomas came up with a concept. It was his. He came up with the name of the character Wolverine and he handed it directly over to John Romita in the bullpen to develop a character sheet, which he gave to Len Wein who was the writer at the time.”

Trimpe continued, “I don’t want to take away anybody's ability to make a few bucks, but it was it Roy's concept and John's character design. The writer in my opinion gave the character a voice and actually collaborated with the artist in terms of bringing the character to life, which is no small thing, but it's not really the originator of the concept.”