The first question to ask in applying these rules is:
When did the repudiating statement or action occur? Before or after (or at the same time as) a breach by non-performance.
In Hochster, De La Tour repudiates before he breaches by non-performance. He repudiates on May 11, and his performance was due on June 1.
Suppose, however, that De La Tour did not make his repudiating statement May 11; instead, he met Hochster on June 1, and they traveled to Paris. In Paris, De La Tour refused to pay Hochster (assume a payment was due when they reached Paris) and announced (definitely and unequivocally) that he was canceling the trip and returning to England.
De La Tour made a repudiating statement that occurred at the same time as his breach by non-performance.