Read this opinion. See the evidence that the trial court -- and the Court of Appeal -- allowed to be admitted. Then ask yourself this question:
Imagine that a retired police officer started up a similar business and wanted to offer nearly identical "expert" testimony on behalf of the defendant. Which basically -- as here -- just summarized the evidence introduced at trial and explained, in essentially the same way that counsel will at closing argument, why this evidence is in favor of the defendant and establishes that he's likely not guilty.
What are the odds that this testimony would be allowed?
I see very little benefit in allowing this sort of testimony. Including but not limited to the testimony admitted here. And lots of dangers.
Notwithstanding the Court of Appeal's opinion.