The former 'Beverly Hills 90210' actor allegedly punched paparazzo Delbert Shaw after he was ''egged on'' by his spouse as they holidayed in Hawaii in December 2010 and the couple were both named in legal papers which were filed in March this year.
Shaw claims Brian hit him in the face and tackled him to the ground as he took pictures of the couple after Megan said to her husband: ''Are you going to let him get away with that?''
However, Brian - who is also accused of throwing Shaw's iPhone into the ocean - and his lawyer claim just because Megan yelled something it does not mean she committed conspiracy and want her removed from the lawsuit.
The papers also claim Shaw is ''physically imposing and notoriously reputed to be a hyper aggressive and physically combative paparazzo''.
The couple - who are expecting their first child together - ''categorically'' deny the allegations saying Brian was merely defending himself from Shaw.
Although the alleged incident happened in December 2010, the lawsuit wasn't filed until 15 months later and the couple's lawyers claim the statue of limitation is up.
A hearing on the matter is set for August 9.