G
gmt1981
I think some of the replies are not understanding what the OP is trying to describe, or I am not.
As I understand it the door wall and brick wall are almost parallel so if the cuts all the way along the brick wall were of equal size then those in the doorway would also be; those at the two ends (under shower tray and the toilet end (to be boxed over, I think)) could easily have been cut to suit.
If the line of narrow cuts, along the brick wall are to be covered with boxing then maybe the effect you are seeing now will be less noticeable and maybe you could live with it. If these cuts are to remain on view then I do not think you are being unreasonable to want it redone (it is only a small floor and the tiler appears to know he had done it badly anyway).
I assume that the end point of the tiling in the doorway was pre-set by your (OP) finishing of the no more ply to where the threshold strip will be. If full tiles had been started from here how big will the cut be along the brick wall?
This is my issue exactly, although others don't quite seem to see it in the same light. I actually have no issue with the cuts by the brick wall as these will be covered, but as you suggest, if the cuts along both sides of the brick/door wall were even on their respective sides (I.e. Not getting wider or narrower) then the whole layout should not veer off to the left (from the shower tray), and therefore the depth of the two tiles in the doorway should be identical.