In situations where an @lert is removed, if the commenting user included a full user name with spaces, only the leading portion of the @lert that doesn't contain any spaces is removed.
For example, in my case people often address @lerts to:
@Rick Sladkey: What about...
and these comments are modified so that they look like this:
Sladkey: What about...
Although spaces in @lerts are not supported, through abuse of the syntax this type of @lert is fairly common. It would be helpful if the rules that removed @lerts could support spaces in the user name so that the commenter doesn't appear to be addressing the post author by his/her last name.
Unlike questions, comments can only be edited by the author so other users cannot fix cases where the removal isn't ideal.