I dont think that your colleague has anything to do with it for two reasons. Even though this watch is very expensive, given his status, this watch is not expensive enough to take the risk. It would not be rational. If you gave it to the taxi driver with his income, that would be more probable. Second, he knows that the watch is scratched and unserviced and because of his background information, he knows that he will not get this serviced because he knows that you are going to report the watch as stolen. So this makes stealing the piece even more uninteresting. He would earn maybe 1/3 of his per year income.
The most plausible explanation is that it was stolen when it was above 9c. This is the only explanation, why not the entire bag was stolen: you simply cant hide it as long as you are on the flight.
So there are two reasons why this seems plausible: - all other times are even more unlikley
- Only explanation why someone did not steal the entire bag.
He thinks he looked at it all the time, but a flight can get boring or there could be something important. You do not check for seat 9c for 3 minutes and you dont even realize that you have not looked. Maybe he got something to drink and couldnt see the place for a moment.
It sounds really hard and im really sorry for you loss because of the bad circumstances, however, i do think that he should not be held accountable. I dont mean it as hard as it sounds, but basically you knew that this is only the second savest way to transport the watch. He is not a professional transporter so he is not as liable as a professional transporter. On a moral perspective: if we are accountable for the favors we do for our friends, someday we would maybe not do anything for our friends anymore because we dont want have costs.
It is such a bad start for you to the new year and i hope that they are going to find the thief. For so long, i think you can buy a very good example of this watch for below 60k, service it entirely and it basically just looks like the watch your wife would have received.
I know, this is not a good solution. Again, im sorry!