And don't forget that physical loneliness, that is, actually being alone, eliminates one major feedback source that something could be wrong with your health, or a source of immediate aid if e.g. you go into cardiac arrest.
Maybe the researcher above touches on these things, but more generally, there should be a standardized probability and statistics exam for ALL aspiring scientific researchers, and a high score should be the minimum cutoff. The influence that a statistically flawed study can have over our collective futures is too dangerous.
It would be more accurate to compare this to a mass crime. 25 feels light for perpetrating one of the biggest and notorious frauds in modern history. Did the judge go to the upper range of the punishment spectrum? There are judges out there who would have made an example out of this case.