mysqldump has this code:

    ( mysql_query_with_error_report(mysql_con, 0, 

                                    ((opt_master_data != 0) ? 

                                        "FLUSH /*!40101 LOCAL */ TABLES" : 

                                        "FLUSH TABLES")) ||

The conditional use of LOCAL seems to come from this mysql bug:

http://bugs.mysql.com/bug.php?id=35157

But I think the patch for that bug is rather confused. I do not think there is
ever a reason for mysqldump to issue a FLUSH TABLES that will be written into
the binlog and replicated to slaves. It should always use LOCAL.

This is particularly serious in 10.0+ where we have GTID. In this case, any
attempt to mysqldump a slave will silently inject a local binlogged
transaction on the slave, which causes that slave to have an alternate future
(extra GTID not present on the master), which is generally a bad thing.

So I propose to fix this in 10.0 by using LOCAL unconditionally.