The radalt alert was set by the navigator at 100m at the very beginning of the tape.
The radalt alert went off between the the 80 and 60 m callouts by the navigator, who was obviously reading off the baro altimeter the way he should, which equals 100 m by the RA due to there being a 30 m deep valley underneath them.
So could we please please put the RA theory to rest finally???