Please help me out here - is that different to the kind of sideslip referred to on p153-154?
Yes.
Fig 73 looks at the effect of malalignment of a bogie with the aircraft following a straight line path. Note how the RH gear is still lined up with the aircraft track.
The French version of the report describes this state as ripé which is simply slip.
If the aircraft as a whole was angularly displaced relative to its track the RH gear would also be showing slip. That is what I mean by
sideslip and the French term would be dérapage.
Once again confusion from English translations!