Scientists are willing to forgive a lot of things, including getting an incorrect result or interpretation. Anyone can make a mistake. Statistical analyses are just that: by chance alone, we sometimes get things wrong. Acknowledging that you are wrong can even win a standing ovation at a scientific conference.
In science, intentional fraud and misrepresentation may be one of the two unforgivable violations of community ethics. Fraudulent publications send people down the wrong paths of research. Claims of success to get grants rob other, honest researchers of their chance at grants. When non-scientists hear about fraud, they often learn to distrust science as a discipline rather than to recognize the admission of fraud as successful self-policing of the stinkers within the community. And when it comes to medicine, fraud costs lives. And with the internet being what it is, a fraudulent result can spread outside the skeptical community of science very rapidly. An excellent example of this problem is the fear of vaccines created through flawed and fraudulent reports. The United States has gone from having virtually no measles, for example (virtually eliminated) to hundreds of reported cases a year–and a climbing rate. Much of this is based on memes sparked by debunked claims concerning autism that are known to be unfounded.
Science is a self-correcting system. When we replicate or fail to replicate results, we ask more questions and do more research. And, as in other communities, most scientists are honest. An analysis of retractions dating back to 1977 shows that most (43%) retractions are due to dishonesty, such as fabrications or falsifications and 10% due to plagiarism—a far smaller percentage stems from errors.
Despite these figures, the bulk of papers and ideas published are honest. People have suggested different reasons why someone would commit academic suicide by committing research fraud. One of the more probable ones is the intense pressure to publish and get grants that have increased since the 1970s.
So what is the other unforgivable violation of scientific ethics? In this century we are finally recognizing human experimentation without choice or informed consent as an abhorrence. For more information on this latter topic, please see Medical Apartheid by H. Washington, and Sentenced to Science by A. M. Homblum. This history of medical abuse has interacted with the induced fear of vaccines to threaten many lives of people: both those who will not get the vaccine and those who cannot get it.