I've Googled "to leg one over", including the quote marks which searches grouped words (worth remembering). Was hoping this would mean 'to stitch up' or 'pull a fast one' , i.e. to 'rip off'. However, no joy. Even then, 'rip off' is not your every day expression for 'leave in a hurry', although rip does mean tear or scarper. . . .
Could also be 'Hop off' for 'Leave' (although casually?) and goes well with 'Leg' . . . . but still all depends on 'Play' so can't really draw a conclusion. Regards, ja