Even so-called scientists make mistakes, yet try to bury the lie so deep you don't know right from wrong.
That line there, that is a massive part of the problem. You see, scientists are human and they do make mistakes, but you know who figures out it was a mistake and corrects it? Scientists.
Science is forced to be correct, because if anyone discovers that it is wrong, science is required to prove itself, it requires retesting, and any time new information comes about that does prove it to be wrong, it has to correct itself, and in doing so it becomes once again correct. The notion that science can't be trusted because scientists make mistakes shows a lack of understanding of the scientific process. Science requires harsh and strict peer review; it begs to be proven wrong. As soon as one scientist makes a claim, they have to be able to prove their claim, and then every other scientist of the same specialty is out to prove them wrong... and when done correctly, it will prove whatever the truth happens to be, whether they like it or not. The peer reviews then get peer reviewed, and so on and on until there is a scientific consensus. A scientific consensus isn't a group of scientists sitting around at a meeting deciding to agree with each other. It's the world-wide body of evidence that proves a fact. Thus, if there are 1000 studies that prove that vaccines don't cause autism and two that don't, the two that don't are the ones that go against the scientific consensus. Those two studies are discarded because and are not correct, and we know they're not correct because a mistake was made in those studies that gave a result that could only be proven when the mistake was repeated.
When scientific research is buried, it's not the scientists that bury it. It's the corporations and governments that forced scientists to sign a non-disclosure agreement before they started working on the project that bury it. The good news is, nothing stays secret forever, someone leaks it eventually and scientists are usually the first whistleblowers. The problems really begin when no one listens to them because they don't trust them, because they don't trust science. It was only very recently in my town that the whistle was blown on the NSW government for sitting on a recent report about environmental lead levels in the town and refusing to release the information due to pressure from the mining companies. Yes, cover ups happen, but it's not science that's doing the coverups. It's science that is screaming into a void that no one is listening to, because we humans don't like being told we're wrong about anything. We don't like it when anything comes along and challenges our cognitive biases.
Another massive problem is bad reporting by the media. This is often used by pseudoscience promoters to "debunk" science and encourage the belief that science can't be trusted because it gets things wrong. A scientific research study suggests that there might be a link between this and that, but further research is required. In other words, they found a correlation and want someone to fund further research on it to find out what is really going on. The media gets hold of it and reports it as this might cause that, which turns the correlation into a causation which is not what the science said. Later on, the science confirms that despite the correlation, once the further study was complete and all factors were taken into account, this didn't cause that at all, it was just a coincidence that this and that tend to commonly happen around the same time. The media then reports it as the science was wrong, this doesn't cause that after all. But by then, everyone has jumped on a social bandwagon of believing this causes that and reacting accordingly. Baby birds are born in Spring, and flowers bloom in Spring, but baby birds being born don't make the flowers bloom.
The last problem is terminology. Science uses many of the same words that general English does, but with different meanings, and a lot of people don't understand the difference.
Theory - in general English it means an idea. In science it means something that has indeed been proven true. An idea that is yet to be proven is a hypothesis.
Consensus - in general English it means a group of people agreeing upon something. A scientific consensus is the massive body of actual evidence that doesn't give a

about anyone's opinion.
Opinion - Anyone can have an opinion about whether or not chocolate or vanilla is the best flavour of ice cream and they can't be wrong about that, because it's a personal opinion. It's an expression of personal preference. A scientific opinion is what science has so far proven to be true. It's not merely the personal opinion of a scientist.
Regardless of language use, the idea that vaccines cause autism is not an opinion. It's incorrect information.
So, when someone says they're allowed to have a difference in opinion about something like that, sure, okay, they're allowed to be wrong.