Whether or not a paper is fully correct is less important that the further work it stimulates or informs-- either via more papers (impact factor) or via APPLICATIONS of the research.
In the example you're giving, to get accepted, the author doesn't need to do much more than extend the research in some small way, compare it to other research, or explore some aspect more fully. If someone is going to take the time to repeat something, they might as well go a little further.
If someone takes the time to apply research results they're going to, in a way, test the validity of the results. Maybe the author's experiences in the pharma world is very different, but I doubt that.
Yes, it should. We have too many demonstrated instances of studies built on other studies that turned out to be flawed, but the second study, rather than showing the first one was flawed, was rationalized and massaged until it conformed to the first study because the first study already had the imprimatur of peer-reviewed correctness on it.
Only someone replicating the original study directly (give or take sample size or duration or other simple such changes) will have the guts and moral authority to stand up and say "I can't replicate this. The original study may be wrong."
(Mostly because they don't publish code nor data; and academic code is often a horrible mess, and the code was mucked around with between different stages of running.)
Often, I find that authors don't publish their code. If they do publish their code, they rarely publish their code for their benchmarks.
— Donald Knuth