Lets look at climate change then. No scientist is claiming to have all the answers regarding climate change. For example no scientist is going to give us a date eg January 15, 2052 for when life on earth will cease to exist due to climate change. However, the scientific community is in agreement that the earth is warming up (by average global temperature), that is warming up faster than it used to 200 years ago, and that all the evidence they currently have suggests human activity is accelerating that warming. They aren't claiming that they are incapable of being wrong (infallible), they are merely stating that they are very confident they are right. Subtle but very important distinction.
People may interpret that as them being sure they are incapable of error, but they aren't actually making that claim for themselves.