Its really sad that we live in a birthing environment where its so much like walking on egg shells. I obviously couldn't lie about my cesarean, but the ringer I was put through because of the laws and attitudes in place in my state, all because of a 10 yr old uterine scar was unbelievable. I was actively persuing a career as a doula and eventually a midwife (have all of my training package/books/etc and had a doula lined up to mentor me), until I got entangled in the web of garbage that surrounds birth in my state. I just knew that I would be unable to sit by and watch it all happen, without "fighting the system" and as a doula, my role would be to support mom even if she was doing something I didnt agree with, and even worse, as a midwife, it would be to follow the rules, stupid as some of them are, or risk persecution. As I said elsewhere, I don't blame midwives, but the system is screwed UP. After awhile it feels like banging your head into a brick wall trying to elicit change.
As for lying about smoking/drinking/etc... Honestly if I'm paying someone to be my care provider, I would want to get the most I possibly could out of it, and I would want to be able to trust them. I don't see that happening if there are lies on either side. The biggest problem I've had with OBs and CNMs that I've headbutted with, is that they lied to me in order to elicit the response they wanted and after I found out about the lies, I could no longer trust them with my care.