As ususal, Buster the cowardly imposter does not know what he is talking about - he only cares about Zubrin's "no planetary protection needed" philosophy because he likes the idea of sending astronauts to Mars on a suicide mission.

Here are Dr. Benton Clark's (lead PI for the NASA Stardust mission)comments showing that the rain of meteorites from Mars is a joke:

MARTIAN METEORITES
What hhs been called the "rain" of martian meteorites can hardly be called a flood. To date, only 0.1% of the tens of thousands of meteorite specimens are identified as of martian origin. This is undoubtedly
too low for estimating the natural frequency of infall because of the bias against identification. Iron meteorites are most common in collections, because they are the most bizarre and easiest to recognize as different from typical terrestrial rocks. From the relative frequencies found in Antarctic and desert-plains meteorites, where few natural terrestrial rocks are present, the lunar and martian meteorites undoubtedly comprise a greater percentage of the infall.
None of the martian meteorites discovered to date are "fresh." All have been in space for between about 500 thousand and 20 million years as revealed by their cosmic ray exposure ages. The same rough scale
of antiquity holds even for a portion of the meteorites coming from our much nearer neighbor, the moon. If martian organisms did arrive "recently", most of them took millions of years to get here. Except for the case of organisms buried deep inside large boulders, it is clear that in such transfers, all organisms would be exterminated by the lethal space environment. In a separate paper (Clark, 2001), the numerous barriers to successful transfer of viable biological materials have been already delineated, with emphasis on certain
of the pertinent factors, such as the in-space radiation sterilization of samples and the improbability of launch of materials which are most likely to be biologically-inhabited (e.g., sediments, aqueous materials,
etc.). It is often pointed out that a small but important fraction of meteorites could arrive here much, much faster (Gladman, 1997; Mileikowsky et al., 2000) and hence survive the multiple threats of ionizing radiation.

From: "Martian meteorites do not eliminate the need for back contamination precautions on sample return missions"

Advances in Space Research, Volume 30, Issue 6, p. 1593-1600