Earlier quoted context omitted.
There’s not a whole lot of room for discretion here though.
Alex frequently bends the rules.
In particular, if a contestant gives an ambiguous or incomplete response such that it's not immediately right nor wrong, it's up to Alex how soon to rule them wrong or how long to wait for the contestant to supply more information. Besides that, the host does have some discretion on whether to accept a close mispronunciation, and if the judges disagree enough then it will be addressed and corrected at the next break.