I know what your saying I'm not sure if it would work though, you could use something like this in your cutscene
?side player == east : goto "EastCutscene"
?side player == West : goto "WestCutscene"
#eastcutscene
blah blah blah
exit
#westcutscene
blah blah blah
exit
try it but I don't know how camera's work in MP