On the wider point:
Why is there an assumption that scientists behave any better or worse, than the population at large, or with any less bias?
Amongst the body scientific, there are all the types of personalities in the world at large. It is A large group of people , the majority of whom are conscientious but fallible at times, but just as in the world around them , there are a few allow ego and hubris & bias to trump proper process. On more controversial topics some allow their perception to be swayed by bias / belief and a few are actually caught cheating.
But that’s people, when were they ever different? Plenty of lawyers and police who supposedly deal in truth have been caught perverting the course of justice too!
The motivations to allow ( shall we call it) “ less than proper diligence” are the usual suspects, money, reputation , a priori bias, backing themselves into a corner. Etc. They are people after all.
The GMP systems of accredited laboratories are designed to eliminate wishful thinking and to mininimize the sometimes inevitable sources of people error, Sadly such process is not always followed.
(it is an aside on this thread that the shambolic dating of the shroud of Turin , caused by a toxic mixture of bias and hubris, The dating ITSELF should have been CALLED OFF and could never have happened had good practice been followed by the parties!
Why? because the AMS labs had utterly failed In prior process qualification and validation!! There was Total lack of essential non conformance process either. The machines and wider processes would have been sidelined pending requalification in an accredited lab. The labs should have shut their doors. It was all swept under the carpet, but how many people know that? That is the reason I urge all to study that period not just a single paper -not that anyone ever does i-, but if anyone wants to explore that, do it on a relevant thread)
As for “ no bias”
One of the oddest flips of logic, is the presumption that around religious phenomena the atheists are by definition more impartial and have less “bias”
A simple piece of logic refutes it. The boot is on the other foot.
In Analysing a so called “ miracle”, the believer does not need any of them to be true. It is of no consequence in any major branch of Christianity, indeed the church has demonstrated it is one of the worst sceptics of all. It is very late to the party in even declaring any “ worthy of belief”.
The believer CAN be impartial without sacrificing belief.
But The atheist NEEDs every single instance of possible “ miracle” to be false, so they ONLY look at the case against, and in few cases they try to misrepresent it!
So on presumption of “bias” , the atheists clearly have not only MOTIVE but also the NECESSITY for bias , and sadly so it has proved in some of the history of such analysis.
I hasten to add - Most scientists are trustworthy in separating belief from science, but sadly not all, ( they are people after all! ) Some of the worst abusers of “bias” have been atheist.