It's Brett McMurphy's fault. I read his bit earlier this morning claiming Mullen was a "finalist" for the Oregon job, and I knew right then that everyone was going to jump on this as proof that Mullen is job hunting. I'm not a "kill the messenger" kind of guy, but McMurphy has proven time and again that his "sources" are usually just fans with no inside information. Just look at his reporting of the Texas job. He would say things like "Strong's job may be in jeapordy, but the President really doesn't want to fire him" (This was after they lost to KANSAS) and "The fact that LSU is looking at Tom Herman may put pressure on Texas to go ahead and fire Strong so that they can go after Herman". These statements were correct, but they were statements that I could have "reported" without talking to anyone.
If McMurphy says Mullen was a "finalist", then I think that just means he and Taggert were the last two coaches left on their short list.
I don't know if Mullen interviewed with Oregon, or if he declined to interview, but I'm not going to guess at Mullen's intentions based on unsubstantiated rumor.