That's why studies are repeated over and over, usually hundreds of times, before we consider their results to be plausible. Anyone that doesn't do that is cheating. Do cheaters exist? Yes, but they always get caught, and the punishments for it are exceedingly severe. That's because dishonesty in science can put lives at risk, so violations cannot be allowed.
I'm not going to spend a lot of time on your post because we basically agree. However, I do want to take one of your points to task. You claim that "[cheaters] always get caught, and the punishments...are exceedingly severe."
I refer you to
http://www.reuters.com/article/us-science-cancer-idUSBRE82R12P20120328 wherein we find that:
QUOTE:
A former researcher at Amgen Inc has found that many basic studies on cancer -- a high proportion of them from university labs -- are unreliable, with grim consequences for producing new medicines in the future.
During a decade as head of global cancer research at Amgen, C. Glenn Begley identified 53 "landmark" publications -- papers in top journals, from reputable labs -- for his team to reproduce. Begley sought to double-check the findings before trying to build on them for drug development.
Result: 47 of the 53 could not be replicated. He described his findings in a commentary piece published on Wednesday in the journal Nature.
"It was shocking," said Begley, now senior vice president of privately held biotechnology company TetraLogic, which develops cancer drugs. "These are the studies the pharmaceutical industry relies on to identify new targets for drug development. But if you're going to place a $1 million or $2 million or $5 million bet on an observation, you need to be sure it's true. As we tried to reproduce these papers we became convinced you can't take anything at face value."
...
Other scientists worry that something less innocuous explains the lack of reproducibility.
Part way through his project to reproduce promising studies, Begley met for breakfast at a cancer conference with the lead scientist of one of the problematic studies.
"We went through the paper line by line, figure by figure," said Begley. "I explained that we re-did their experiment 50 times and never got their result. He said they'd done it six times and got this result once, but put it in the paper because it made the best story. It's very disillusioning."
Such selective publication is just one reason the scientific literature is peppered with incorrect results.
For one thing, basic science studies are rarely "blinded" the way clinical trials are. That is, researchers know which cell line or mouse got a treatment or had cancer. That can be a problem when data are subject to interpretation, as a researcher who is intellectually invested in a theory is more likely to interpret ambiguous evidence in its favor.
The problem goes beyond cancer.
On Tuesday, a committee of the National Academy of Sciences heard testimony that the number of scientific papers that had to be retracted increased more than tenfold over the last decade; the number of journal articles published rose only 44 percent.
Ferric Fang of the University of Washington, speaking to the panel, said he blamed a hypercompetitive academic environment that fosters poor science and even fraud, as too many researchers compete for diminishing funding.
"The surest ticket to getting a grant or job is getting published in a high-profile journal," said Fang. "This is an unhealthy belief that can lead a scientist to engage in sensationalism and sometimes even dishonest behavior."
ENDQUOTE.