Thanks, Cogsim:
0210 34-43-00-5 WRN NAV
TCAS FAULT
Loss of ADR1 to Transponder 1 (if selected) or Loss of ADR2 to Transponder2 (if selected)
Loss of Mode C.
This is downstream of loss of ADR.
Loss of Mode C results in TCAS Off, not TCAS Fail.
I can only conclude the BEA reporting is inaccurate.