My EOS 50e (Elan IIe) never fogged any Rollei IR-400 (that goes to about 820, if I remember correctly). Only very slight darkening right around the sprocket holes, but that could have been a developement error as well.
And no, there is no way to disable the little IR-lamp, as it's the cameras way to count the sprocket holes until the next frame. If you'd put a piece of tape over it, the camera would either respond with some obscure error code or by spooling the whole film at once without ever stopping.