Not to gravedig this thread, but just wanted to provide a quick update -- TK got back to my friend with the following (choice of) offers:

1) 42k Bonus Miles
2) 18k Status Miles
3) Roundtrip Economy Flight
4) Upgrade of Round-Trip Flight to Business Class
5) Traveler's Cheque 780€ Usable on TK
6) Refund Cheque 600€ in "cash" (appears to be issued as a traveler's cheque)

Sounds like he got the desired resolution in the end (#6), though navigating TK customer service has sounded quite Kafkaesque from what he's described to me.