@TTex600:
It may have been a partial failure (i.e. loss of speed, as they would all have been getting), or if the RHS air data computer appeared to be getting dodgy pitot and static input then it may have dropped altimeter as well. In the sim, the closest visual approximation my colleague could get was to fail the ADC on my (RHS) side completely, which left me with attitude (artificial horizon) only. I could read the altimeter and see it winding down on the standby though, so I used that rather than make the TRE switch the source for me.
A possible theory, and I'm not saying it's true, is that manual handling was trained in terms of following the Flight Director, and the PF could have been referring to losing that.
The other question is, if the PF really was referring to losing all indications - why did he not hand over control at that point?