When you are typing a new comment or editing an existing comment, if you @lert 2 people you get the warning saying you can only @lert 1 person. This is of course by design.
However, if you remove the @lert of the second person within 5 seconds and then hit the button to submit the comment you receive an error saying you can only comment once every 5 seconds.
I believe the code that establishes having submitted a comment should come after the code that checks to see if you are @lerting 2 people. That way once the @lert is fixed you wont get the 5 second error message.