The Wall Street Journal (and the often informed Yukari Iwatani Kane) are reporting that while it's unknown how much iPhone 4 antennagate and white iPhone 4 delays played in SVP of mobile hardware, Mark Papermaster's exit from Apple, there were broader cultural issues at play:

Mr. Papermaster had lost the confidence of Mr. Jobs months ago and hasn't been part of the decision-making process for some time, these people said. They added that Mr. Papermaster didn't appear to have the type of creative thinking expected at Apple and wasn't used to Apple's corporate culture, where even senior executives are expected to keep on top of the smallest details of their areas of responsibility and often have to handle many tasks directly, as opposed to delegating them.

One of these people also said Mr. Papermaster had difficulty maneuvering Apple's internal politics.

The WSJ does say it was Steve Jobs, not Papermaster, who decided to go ahead with iPhone 4's new antenna design.

Papermaster apparently also started his tenure with Apple while Jobs was on leave of absence and might not have been prepared for Jobs' intense management style when he came back to work.