keepatit
Like xwordfan, I worked back and got the only possible thematic answer.
The problem is the parsing. The use of the word "by" in the clue conventially means that the first part is put before the second, so A by B means BA and not AB. Thus the clue as written gives ****MIS, not MIS****.
The clue should read "Jim's set off energetic person". Then the cluelets are in order.