Attempting to return a value from a subprogram shows no error and internally fails

[expositionrabbit]

Sub subprogram()
    Return "I am breaking the law"
EndSub

subprogram()

No error is shown in the editor. Trying to run puts uncaught exception: [object Object] to the console, hinting at an internal failure. However, innoncent children do not know how to open the console and would appreciate a visible error.