As I understand it, cpdlcads, the Rudder Travel Limiter does indeed restrict rudder movement to 4 degrees or so at high speed. As opposed to 30 degrees or so at low speed.
BUT, it surely relies on the ASIs for the speed? If the pitot tubes were partially blocked, presumably the ASIs would understate that speed?
So could the RTL, in those circumstances, have permitted a much greater rudder deflection than was safe?