I'm not sure whether they are right.
A javadoc comment block should start with "/**" and not with more than two asterisks in my opinion.
According to the doxygen-docs, you should use somthing like this "/**********//**", if you want to use a line of asterisks to make a comment block more visibly.
See here:
http://www.stack.nl/~dimitri/doxygen/docblocks.html (listpoint 4.).
I just tested it with doxygen and it ignores blocks starting with more than two asterisks.
So it might be lexer error, but as written before I am not sure.
According to the javadoc-reference there must be a leading "/**" and a trailing "*/", but leading asterisks are allowed in each line, and if everything after "/**" is treated as line, all following asterisks in the first line should be ignored and it's a doxygen-bug not to do so.
But that's something that should be discussed at another place (doxygen, javadoc forum/mailing list perhaps).