Just a wee thought - going back to earlier posts re ATC's responsibility for preventing collisions on the manoevring area.
Yes ATC are responsible for preventing collisions between aircraft on the MA, but let's go to the logical conclusion. If you given TAXI instructions to taxi to a holding point (NB- not a clearance ! clearances are only for crossing, line-up or landing on RUNWAYS ) then how often can you remember being told that there is an aircraft in front of you on the taxiway or at the hold ??
So yes, ATC will be normally responsible for preventing crossing confliction type collisions but as for "shunt" type occurrences - which I believe covers this case - I think most pilots will accept that they should be aware of what is "in front" at the hold , even if this means at a small angle separated away from the direction of travel of their aircraft. Still the Swiss cheese theory holds water...........or not as the case may be.