Is there something a math teacher can do that a science teacher
The essence of the mathematical discipline is rigorous deductive proof. Feel free to read that as "correct and understandable explanations and justifications" for mathematical principles.
Frequently, non-math science teachers have only taken computational math courses in college, like calculus, differential equations, and linear algebra (likely in their first two years or so).
But for college math majors, there is a radical shift around the end of the second year: courses suddenly shift to being about writing and understanding proofs as their central focus (generally talking U.S. system here; in other locales they wouldn't wait that long). It's common for math majors who are only good at mechanical calculations to find this very difficult or switch to another major as a result. Science majors usually never see these courses. (Conversely, some people who would be very good actual math majors never get through the mechanical-calculating prerequisites to get to this point.)
So it's quite likely that science teachers, given their background, could present a calculating algorithm, but be unable to explain why the method works. Not being trained and practiced in how to carefully attend to starting definitions and theorem-construction, it's quite likely that it would come out as a mishmash and be unclear on what the symbols, operations, starting assumptions, and sufficient and necessary conditions really are (in fact: I often experience this when I try to read posts on SE Physics, say).
Overall, such a mode of presentation represents cargo-cult (or faith-based) math, and leaves students unable to succeed at the next level, because all they're doing is memorizing a ton of separate facts instead of understanding more broadly-applicable principles.