Note that the Emit system is not used to time the runners at WOC. It is only used for punch control and splits.
Actually, the SI system and the Emit system were never designed to be accurate timing systems. They were engineered to replace the huge manual labour of checking the needle punches. Up to a quarter million needle punches every day at events like O-ringen. As a bonus you get splits, but who cares if they are off by a second or two? The clocks in the systems are cheap and drift a lot.
When I started running events with electronic punching in Sweden in the mid 90s, the system was only used to replace needle punching and to give splits. Later, organizers started to use the systems to time the runners as well, but I think it's obvious when you work with the systems that they do not have the accuracy and reliability needed for a big championship.
Also, Emit is a Norwegian company. Norway use only Emit. Some province federations in Sweden and Finland bought the system in the 90s, so you see it here and there in those countries. SI is a German company and they completely dominate in continental Europe and have also a big part of the market in Sweden. Not as much in Finland.
If you're interested in the history of these systems and how they work, I wrote this long article in Due West last winter:
http://www.orienteeringbc.ca/duewest/DueWestFeb200...