British English has many unkind words for a person who insists on the exact terms.
A jobsworth: An official who applies small rules to the letter, whatever the result.
A stickler: A person who insists on exact rules.
A barrack-room lawyer: A person who argues over the wording of rules, usually to avoid a duty.
A box-ticking exercise: Following a procedure without caring about its purpose.
That’s a bit petty: That is technically correct but unreasonable.
It’s not cricket: It is unfair, even if it is allowed.