An engineer has told the trial of a British Columbia mayor charged with public mischief that broken bones may not be the result if someone's foot is run over by a car.

Dennis Chimich, an expert in the biomechanics of bone fractures, testified for Doug McCallum's defence team, which is presenting evidence to suggest their client was not lying when he told police a woman ran over his foot in a grocery store parking lot.

McCallum filed a complaint with the RCMP in September 2021, saying that a woman whom he had a toxic relationship with over his policies targeted him with her vehicle.

Chimich told the provincial court trial that he calculated that the rear right wheel of Debi Johnstone's car could have caused soft tissue damage as indicated in a medical report he examined.

However, Crown attorney Richard Fowler has suggested a study Chimich relied on to prepare a report involved cadavers' feet being run over by a car and that swelling in a live person could result from other factors including age, fluid retention and medications.

The lead RCMP investigator in the case has testified surveillance video from the store is inconclusive in determining whether McCallum's foot was run over but there's enough evidence to suggest some of his allegations were false.