Is it wrong to unintentionally withhold information?
If you were not aware, you did not "withhold" because that requires intention. 

With time, you will practice insight about what implicit assumptions you make - this is part of the scientific development and even great scientists have not been free of that. Galilei transformation, for instance, was taken for granted for centuries, which was initially fine, but was sustained to the point where "ethereal" concept-bending had to be introduced to keep it alive. 

As Einstein said: "The fish is last to discover water." Do not be too hard on yourself, as long as you put it firmly into your agenda to do your best to be fully aware of your assumptions and their validity. Discussion with friends/colleagues can help here.