Revealing mistake: When Rick checks his revolver before holstering it, there are no primers in his cartridges.
No Sanctuary - S5-E1
Revealing mistake: When Sam has his throat slit, the location of the wound does not correlate with where the blade was shown to be slicing the skin.
Revealing mistake: After it starts raining there is a shot looking at the road in The Distance. Notice how the rain is only falling in a small area and stops just beyond where the group is at. The road is dry from there on out.
Answer: No, she actually tries to talk Rick out of it, but he's already made up his mind, minutes later when Daryl asks him about the location of his brother Lori says "he'll show you."