Via @ScarbsF1 on twitter,
An australian company helped Ilmor (Mercedes) develop an innovative, lighter, more powerful, and more durable V10 engine, the first prototype of which was built at the start of 2004.
http://www.v-eight.com/multimedia/pdf/AutoTechBRV.pdf
A few months later the FIA banned the rotary valve before it had ever seen the inside of an F1 car.
Noooooooooooooooothing to do with Ferrari’s Technical Veto that was in force at the time, I’m sure.