Technically, as in "what does the paperwork say", of course, you're right. Though the Deepwater Horizon had drilled under lease to BP since it was built - before Transocean was even involved. Your headline makes it sound like BP just borrowed a screwdriver from them, rather than having had exclusive use of this rig since inception.

Clearly you don't do much mission critical business computing. Cause if you did you'd probably understand the respect Oracle/Sun gets in the trenches. All this stuff (Zones, ZFS, DTrace) are used heavily where I work, which is a pretty damned large "business critical computing" company... and it's not Oracle. ; )