Yeah, try this
index=... sourcetype=... | stats count(watch) by president | search president="Bush_W" | rename count(watch) AS passed_to_secret_service_agent | eval where_is_stolen_watch=if(passed_to_secret_service_agent>0,"The U.S. gov forgot to give it back","The watch was stolen") | table president where_is_stolen_watch
Indeed, you'd have to table all the presidents afterwards and fillnull to get those zeroes, that could get tedious, are we also assuming that both pocket and wrist have been classified under the watch field?
Line 3 will narrow down to only search "Bush_W". When I googled this scenario, the first thing I saw was that the secret service grabbed it before it was stolen and never gave it back, so I went with it. The answer will always return this if that president ever owned a watch
**President** | **Where_is_stolen_watch** Bush_W | "The U.S. gov forgot to give it back
SInce there are so many presidents and watches in the index, you'd want to be in the habit of checking identity of the president first, rather than wasting all those mips counting up the other couple of hundred records.
Also, since typists may get confused between the various George Bush presidents, and because the name can appear in various forms, you might be better off testing for something like...
| search (first_name="George" AND last_name="Bush") OR president_number = 43