Here are some quotes from Stoner's interview with Motosprint published in several publications. These articles were all published on or about January 6, 2016.
(
http://www.autosport.com/news/report.php/id/122383):
"It's not the same," he told Motosprint when asked how the Ducati role would compare to his Honda position.
"At Honda I was just an occasional tester, I did not have any other role and, to tell you the truth, they never took full advantage of my potential.
"
I think Marquez and all his entourage felt threatened by me. I don't know why they thought that, but that's my feeling."
"I was at Honda to do some testing, to try new things that could then be transferred to the works riders, so I was there to help Marc.
"But it's also true that the number one rider is the one everyone must follow.
"I have no grudge against Honda. And I have great respect for [HRC vice president Shuhei] Nakamoto. As a matter of fact I'm certain that our relationship has not deteriorated for this and that we'll get on well."
http://www.crash.net/motogp/news/225999/1/stoner-marquez-felt-threatened.html:
"At Honda I was just an occasional tester and wasn't being used to my potential," Stoner said to Motosprint. "I loved working with the HRC guys but
I think Marc and his crew felt in some way threatened by me and I don't know why. I was just there to test and help.
Fox Sports Australia (
http://www.foxsports.com.au/breaking-news/motogp-casey-stoner-believes-marc-marquez-felt-threatened-by-his-presence-as-hondas-test-rider/news-story/b43a0777efafdfd21824af9068e5b98a)
“
I think Marquez and all his entourage felt threatened by me. I don’t know why they thought that, but that’s my feeling.