Not hard to tell who the bookies are
Funny thing, these guys scream about "human error" and the "right" for a book to cancel an error ...
... but apparently they don't think that the humans that bet make human errors.
Now, of course, there is a FINE line here. If you make a mistake & call back immediately (and the line has NOT moved against you) then for a book to NOT appreciate human error make them SCUM IMO.
No two ways about it - ethical play is a TWO way street.