The photo you attached was too big. It needs to be re-sized (maximum) 1200pix wide and 1000pix high.
The only reference or guide I know of is the NHBC's - "A consistent approach to finishes"
1.2 - S1 External walls shall be built to appropriate tolerances
(e) plumb of wall
Maximum 8mm out of plumb for walls up to 5m in height, limited to 8mm in a storey height (approx 2.5m).
Maximum 12mm out of plumb for walls over 5m in height, limited to 8mm in a storey height (approx 2.5m).
(f) straightness in section
± 8mm maximum deviation in any 2.5m height of wall.
No doubt it will be "within tolerance" - a bodging housebuilder's favourite phrase.
But you have seen it and it isnt right. This central pier is supporting the roof structure and is important it is perfectly plumb.
My guess is they built it in or out so it would line through when they got to the lintel?