CF6-50 (& -6), as well as similar vintage R-R and PW engines, are "part throttle" engines at takeoff. All would be more or less overboosted if run at the max stop. The OEM may (& probably does) require some sort of inspection before the next flight.
In most cases such an overboost will be fairly minor, but still is a no-no.
And thank you Denti for reminding us of Vmga & Vmcg limitations. Flying sideways is not a good thing.