In the Journal of Halacha and Contemporary Society (LVII - love the classy Roman numerals!), Howard J. Apfel, a pediatric cardiologist, rabbi, and teacher at the boys' high school of Yeshiva University, presents a thoughtful and detailed article entitled "Life-saving duties on Shabbat: switching call with a nonobservant Jew."
This being an Orthodox journal, there are a number of premises I don't agree with. The first(implied but present nonetheless) is that all Jews are either "observant" or "non-observant." In reality, while Jewish religious observance is a spectrum, what the author means here by "observance" is membership in the [ultra-?]Orthodox community, which has certain sociological criteria. Thus, while I'm an observant doctor, I am not an "observant" doctor for the purposes of this article.
The second premise is that contemporary halachic decision-making must be attendant on the gnomic public pronouncements of great ultra-Orthodox rabbis. We've talked about this.
But putting those premises aside, there's something else to talk about:
"[W]hile the non-observant doctor or soldier fully intends to save life, they are also deliberately doing the prohibited actions involved [on the Sabbath] for personal gain (for example to receive their pay, or to avoid being fired or prosecuted) as well."
I won't go into the details of the halachic argument, but I will point out that the understanding of motivations here is deficient. Doctors, soldiers, and other people walk around with multiple motivations, some of them primary, some of them secondary. Some of these motivations recede into the background and on occasion cannot even be recognized by the person so motivated. But in the majority of cases, people aren't motivated this way at all! No one thinks, "I need to put in these medication orders or I won't get paid"; "if I don't go check on the patient, I'll get fired"; "if I don't put in this IV, someone will sue me successfully."
Well, maybe some doctors do, but not the good ones.