Just to note. The article isn't talking about meteorities at all. For the sake of argument though, the probability of microbial transfer from either Earth or Mars in the period known as the late bombardment period certainly could have occured. Perhaps Earth and mars were very similar then. But if Earth microbes were transferred to Mars during this time and they survived, they would have evolved to the changing conditions there and could be pathogenic to Earth life today. Carl Sagan knew this in his article for The Planetary Report in 1996.

For a good report on the limits of microbial surviaval and transfer in meteorities I recommend this excellent paper, peer reviewed and published in ICARUS:

PLANETARY INTERCHANGE OF BIOACTIVE MATERIAL:
PROBABILITY FACTORS AND IMPLICATIONS
BENTON C. CLARK
Lockheed Martin Astronautics, POB 179, Denver, CO, 80201, U.S.A.
(Received 5 November, 1999)

Abstract.

It is now well-accepted that both lunar and martian materials are represented in the meteorite
collections. Early suggestions that viable organisms might survive natural transport between
planets have not yet been thoroughly examined. The concept of Planetary Interchange of Bioactive
Material (PIBM) is potentially relevant to the conditions under which life originated. PIBM has
been also invoked to infer that the potential danger to Earth from martian materials is non-existent,
an inference with, however, many pitfalls. Numerous impediments to efficient transfer of viable
organisms exist. In this work, the lethality of space radiation during long transients and the biasing
of launched objects toward materials unlikely to host abundant organisms are examined and shown
to reduce the likelihood of successful transfer by orders of magnitude. It is also shown that martian
meteorites studied to date assuredly have been subjected to sterilizing levels of ionizing radiation
in space. PIBM considerations apply to both the solar system locale(s) of the origin of life and to
the applicability of planetary protection protocols to preserve the biospheres of planetary bodies,
including our own.

If microbial spores can only survive exposure to galactic radiation in meteorites under 100,000 years in space, then that greatly reduces the chance of any microbial transfer of Martian microbes today. EETA 79001, the youngest of the Martian meteorities has a space exposure age of 160,000 years.