Your argument that Superman is a murderer would make a much better source of compost.
Ok, he tricked (the kneel), tortured (see the hand) and caused severe harm to a harmless depowered individual who very likely died as a consequence (throwing him down a sheer crystal face) and showed no remorse (the smirk).
If he did die as a consequence (which he almost certainly did barring there being a convenient truckload of feathered mattresses at the bottom) any sensible court would view throwing him off the cliff as murder.
Happy now?
Would you like some of that compost for your lawn?
And they could have added a throwaway (dubbed, if they couldn't shoot new scenes) line like "I wonder how Zod and his fellows are coping with being imprisoned in a Earth jail without their powers" or something like that, but they deliberately chose not to do that.
Uhuh, the lack of reference afterwards does somewhat suggest the fall down the sheer face onto rock hard crystals might well have been every bit as fatal as one would sensibly expect....you know the fall Superman caused and did nothing to prevent despite having the ability to, y'know, fly and all that jazz
