I'm not exactly an electrical engineer, but wireless mice mostly use RF around 900 Mhz, and clearly the frequencies used for navigation are nowhere close to that. The FCC has pretty tight reigns on frequencies.

http://www.ntia.doc.gov/osmhome/allochrt.pdf

But I could see why they wouldn't want a wireless mouse being used. I assume things that transmit could possibly be used as a homing beacon for use by less than nice people, so they just put a blanket statement forbidding any electronics that are transmission capable.