Hi All,
I had a problem with this too and posted an entry on Big Dave's Telegraph Crossword Blog -
bigdave44.com - which I recommend to anyone who attempts Telegraph crosswords.
However, after I'd done that to confirm that I did have the correct answer, I checked Chambers and found that 'see off' is given as a slang definition of reprimand. And that was news to me!
Best wishes,
Caravaggio