re: Clear evidence BD has no integrity
While the meteors received so far could be just a small sample it is significant that no life signs have been found in any of them. In a sense that is a blow against both sides of the argument. Panspermia may not work at all in which case life on Mars could be dangerous for here. On the other hand no life in the meteors implies there is no life there to worry about anyway. The ways out of that seem to be only two. Whether there are not enough meteors to be sure or the meteors naturally come from strata that would have no life signs anyway. For example if you blew a meteor out of a big chunk of quartz from a mountain it might not be able to contain most forms of life anyway.