Bud did not think she ran away because she was frightened; she had seemed too sure of herself for that.
She had probably gone for help.
A swift suspicion that the attack might have been made from jealousy died when Bud looked again at his prisoner.

The man was swarthy, low of brow--part Indian, by the look of him.

Honey would never give the fellow a second thought.

So that brought him to the supposition that robbery had been intended, and the inference was made more logical when Bud remembered that Marian had warned him against something of the sort.
Probably he and Honey had been followed into the Sinks, and even though Bud had not seen this man at the races, his partner up on the ridge might have been there.

It was all very simple, and Bud, having arrived at the obvious conclusion, touched Stopper into a lope and arrived at Little Lost just as Dave Truman and three of his men were riding down into Sunk Creek ford on their way to the Sinks.