Finger tight. Which hand? I'm right-handed but arthritis means my grip between thumb and forefinger is weaker. (This has many disadvantages). I do remember 'finger tight', for example when loosely assembling something so it doesn't fall apart, having partially dismantled it to gain access to another area. In any case, try tightening a philidas stiffnut finger tight. There'd be no threads protruding. The end of the bolt would be half way down inside the nut. Even 'finger tight plus half a turn', which is taught in some applications, wouldn't be enough. If by some chance you could overcome residual torque with your fingers, then the nut is scrap anyway.
But as I said, simply not applicable to a safety critical part that must be free to move. This all needs rewording.
What document does a maintainer have when working at the aircraft? Not RA4266. Nor Def Stan 00-970, as claimed by MoD & HSE. He has the AP (not written by M-B), his trade training (whatever that may be), common sense and engineering judgement.
Edited to add. After the accident, M-B issued SIL704, which said 'flush', not one or 1.5 thread pitches. As MoD (specifically the Service Inquiry/MAA according to the evidence) required this, why has RA4266 not been updated? Is this just applicable to Mk10B seats? To the RAF only? To all stiffnut applications? As the CAA promulgated this SIL, the world and his dog must now be thoroughly confused.