I'm making an assumption here, but he may be referring to Remington bolts that have the Sako extractor modification done to them.
In the event of a case separation, or rupture, the extractor can be ejected almost straight back into your eye or forehead (there are documented examples). This is on REMINGTON CONVERSIONS ONLY. The conversion process CAN place the extractor in the bolt raceway where it isn't contained (it can also be done so this won't happen). This is also why these conversions often throw the brass into the scope windage turret. The M16 style conversion is safer, IMO, due ot the pinned extractor and no through holes in the bolt. Often the Sako converter drills the extractor retention hole completely through the bolt. This isn't proper, IMO. That through hole allows gas to push the extractor out making the situation worse. You don't need to drill that hole all the way through.
On a Tikka, or Sako (2 lug), the extractor is placed lower and undercuts the bolt locking lug. In this design, the extractor rotates further and is contained in the ring in the event of a rupture. Some Sako's have a guide bar that also is intended to prevent issues.
This is just my knowledge of the subject. There could be instances of extractor issues on Sako made actions, but I am not aware of any.
Jeremy
