It seems to me it is the people who know very little about science who do not understand some of the basic principles of practicing science:
1. Whenever you make an observation or measurement you need to consider the impact you have on what you are measuring - this is very important, for example, at the sub-atomic level 2. There are always some errors and always will be 3. There is always some level of uncertainty and always will be
The best scientists know how to deal with these things.