Lock In?

You're wrong. The study states plainly that the entity trialing the switch used extensively access, visual basic macros, "office applications" (applications developed within office), sharepoint, etc

You should not underestimate the drag capability of the "advanced" facilities software vendors propose (and MS is pretty good at it). A well-managed IT organisation that religiously hunted down activeX, refused to deploy sharepoint, made its people deploy business code in backend servers instead of using access+vba shortcuts will have no difficulty switching vendors when the cost is right (and it is now). It will have used a standard browser as the information system access tool when MS tries to trick you in using Office instead.

A badly managed organization OTOH will have used all those features because is was "easy" and "free/already paid for" and will blame its unability to switch products on "uncertain TCO/ROI" when in fact the huge sums they continue to pay to the historical provider are the actual bill of all this "free" "easy" automation. And it will end up with huge citrix farms of vista+office 200x and wonder why others are not in the same license pit hell.

When all's said, the biggest functional difference between ODF and OOXML is all the business automation/sharepoint sugar present in the second and not in the first one. In other words, ODF lacked all the gadgets MS uses to install rampant lock-in. That's why MS fought it to the death.