With no one else on the premises, he could tackle correspondence, do some professional reading and sort out the schedule for the next seven days without being disturbed by things like phone calls.
And if the centre's phone did ring, it went unanswered until the voice mail message kicked in.
Unless, of course, the call came in on his iPhone, which could identify the caller, assuming he or she was one of the couple of thousand names in Ballantyne's Contacts list.
Having seen who it was, he could then decide whether to answer.
But the mobile didn't ring that often.
And when it did, Siri never came up with Unknown Caller.
But on this particular Saturday afternoon, after Ballantyne had let himself in the ringtone chimed up, and Siri announced that she was clueless as far as the caller's identity was concerned.
Under normal circumstances, he wouldn't have taken the call, but these weren't normal circumstances.
Still, when he did flick the button across, he kept things to a noncommittal Hello?
The voice on the other end of the line identified itself as Brian Moran and went on to indicate that he drove past the surgery a couple of minutes ago, saw your car in the car park and wanted to know if Ballantyne had a few minutes to discuss something important.
Since his version of the bush telegraph suggested such a call was a strong possibility, Ballantyne had the requisite few minutes.