Sometimes it's not the engineers fault that nothing happens
As a field service engineer, I've had work flows like the following:
1. Turn up at customers premises, fix fault
2. Phone head office to test the fix has worked
3. Find out that the person who was supposed to be doing the test has buggered off to lunch
4. Wait in van
5. Ring up later and find out the said person has not come back into the office yet
6. Wait in van
7. Ring up again and find out that said person has left for the day and their replacement can't find the account details/notes/etc
8. Wait in van
If you are waiting on someone else in a office to do something, there's nothing you can do except wait.