Scientific knowledge evolves as new discoveries are made, immutable and unequivocal “truth” is the realm of religion, not science (which makes the former much more appealing to many than the latter).
Trust really should not erode if X acted in good faith based on the consensus knowledge at the time.
If the consensus is evolving, sure. If the consensus is going back and forth for decades, and each time it is presented with the authority of medical or physical science, then it is normal and correct to stop listening at some point.
When scientists have weak theories that they're not sure of, they're not supposed to share those breathlessly with the public, and certainly not try to shape public laws based on the theories they know are weak.
And nutrition science has been guilty of this for over a century. You can find people in the field making confident recommendations and setting dietary standards from the time when they didn't know vitamins were a thing. If you followed the science on nutrition and adjusted your diet accordingly around 150-100 years ago, you could literally get scurvy or other vitamin deficiencies. The field has evolved a little bit, but it's still extremely weak as scientific fields go.
Scientific knowledge evolves as new discoveries are made, immutable and unequivocal “truth” is the realm of religion, not science (which makes the former much more appealing to many than the latter).
Trust really should not erode if X acted in good faith based on the consensus knowledge at the time.