Optical Image Stabiization vs In Body Image Stabilization - OIS vs IBIS

I was looking at the OM-D E-M5 and I like the 5 axis In Body Image Stabilization (IBIS )because I have the option to use lagacy glass with IS if I want (with Olys recent firmware update). But then I noticed the following comparison on Youtube.

http://www.youtube.com/watch?v=zSMU4FTFnDY&feature=plcp

Never mind the iPhone, I opened two browser windows side by side and qued up the video from the E-M5 wich has IBIS and the PEN which has Optical Image Stabilization (OIS) (links to each seperate video below the triple stack video) and played them together.

I seems that the verticals of the buildings have more wobble in the PEN video than the E-M5 video. I know that this is often caused by rolling shutter from leteral movement. But wouldn't these two cameras have the same issue? If so, then why the difference? Do the moving optics in the OIS add to the rolling shutter effect? The stabilization in the E-M5 has 5 axis stability control. So does it add some rotational compensation for lateral movement to compensate for rolling shutter effect? That would make sense but that is scarry nice.

Any ideas? Does anyone else see the difference?