I guess I am guilty of lying to patients if you count lying by omission. In that I don't tell them, "your baby is having xyz decel, which means xyz, which means we need to do xyz intervention." I actually did do that when I was a newer L&D nurse way back in the day, but learned very quickly to not do it because yes, it freaked patients out, to be honest.
People have very selective memories in stressful situations, and filter out a lot of what they are hearing when under extreme stress. Labor and birth, for most people, is VERY stressful, and their memories of it are really skewed. If something they perceive as "bad" happens, that sticks in their mind and they grab onto that and focus on it, even years later. The same with something they perceive as exceptionally "good" happening. It stays with them. For this reason, I try to really minimize any sort of stress inducing communications with my patients at the bedside. Especially with a first time mom. My poker face is well honed now, as is my "calm voice," and those things have served me well when the poo is hitting the fan and I am screaming in my head but trying to not freak out the patient.
So I guess what I'm saying is, yeah, I kind of lie by omission in that I don't really get into the nitty gritty details of the fhr tracing unless I need to do a major intervention like knee chest, trendelenburg, hold up a cord prolapse, or run for a crash c-section. If the tracing is worsening and I can read the writing on the walls, I will calmly let the patient know bit by bit that there are some concerns, and explain as gently as possible what it happening and try not to scare them. Patients who are scared tend to freeze and fall apart and not cooperate, and that can be dangerous. I have seen it in action at the bedside, and it's awful, and I do my best to avoid that as much as I can while still giving the patient the information they need.