Flap asymmetry can be a very big problem.
Recall the UA DC-10 at Chicago when significant items were damaged when the engine came off the pylon. And then there's the one I had in a Viper long ago.
In my case, the FBW flight controls helped me a lot! The assymetry brake sensor was outboard, and my failure was with the connection to the flap drive motor in the fuselage. The "brake" couldn't work because the flap was not connected to any control mechanism. Duh.
My understanding of the flap control surfaces on this plane is that they are independent from side-to-side. So as with my "problem", one side could fail and the other worked per normal.
At slow speed and with assymetrical flaps you could have a serious inpact on total lift for the plane and also have roll problems due to more lift on one wing than the other. My problem happened after I was above the minimum control speed so I mainly had a lot of drag and used all but 1 pound of stick authority to keep control( according to data recorder we had on early Vipers).
Unless those guys pushed forward right away and reduced AoA/pitch to gain speed, they were doomed.