Here are a few ways to continue that sentence, showing the different possible referents of "he":

- (he = the doctor) "The doctor phoned the nurse because he was late and needed her to start the rounds without him."
- (he = the nurse) "The doctor phoned the nurse because he was late and wanted to know when he would arrive."
- (clearer phrasing, doctor late) "The doctor phoned the nurse to tell her that he, the doctor, was running late."
- (clearer phrasing, nurse late) "The doctor phoned the nurse to ask whether the nurse had been delayed."
- (playful/ambiguous) "The doctor phoned the nurse because he was late—though neither would admit who 'he' was."

If you want a single, unambiguous continuation, tell me which person you mean (the doctor or the nurse) and I’ll finish it.
