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HSS/FP sync isn't triggered through the common center contact on the camera's hot shoe, but through the "special feature" pins. Canon and Nikon use different pin layouts, and so are not interoperable.
Fuji cameras used to use the same layout as Nikon, if I recall, but I don't know about Olympus; it looks the same as the Canon layout, but I don't know if each position carries the same data.
[Edit] According to some Web browsing, the pin layouts of Canon and Olympus are the same, but some users have reported that the foot-to-shoe fit of some third-party flash guns and radio triggers intended for Canon don't fit properly in the Olympus and Panasonic shoes, preventing good contact.