As a last resort,and I do mean a LAST /"you ain't gonna kill me you son of a bitch" resort, a call to ATC that you are going around/deviating to avoid a storm/whatever, is infinitely preferable to wrestling for control.I have only had to do it once in my career when one a**-hole(and that is believe me a kind description of the Captain concerned )wanted to fly straight through a line squall over the Pyrenees and ignored my pleas that I most certainly didn't want to ;it worked, but the ambience for the remainder of the flight and subsequent sector was in itself a pretty big flight safety hazard.I never filed a report,and neither did he,which kind of said it all.I'm happy to say that no F/O has felt the need to do the same to me,in spite of my best efforts on occasions. . .