I cannot speak for Mark. I believe in the Incarnation as one of the central mysteries of Christianity. I do not believe that at any time Jesus was merely a man.
Mark has told us he does not believe Paul was Trinitarian.
"Paul definitely is not Trinitarian." -- Posted by MarkBsnr on April 24, 2010.
Mark asked me a strange question. He wrote "In some cases, Paul called Jesus a man and not God. Do you have anything to say about that?"
Now from that sentence and his earlier remark we can understand Mark seems to be saying Paul believed Jesus was a man, but not God.
Do you agree with his supposition?