Hi Lancer, I am a independent life insurance agent for ING (lion icon) and I've dealt with multiple clients. I've actually had a client who told me that she smoked once or twice before the medical exam but she still was able to get the best health rate because ING is a big company so we are very competitive and have the flexibility to qualify many people as the best rate.
As for you, I'm not sure what company you are applying for but if in the case you don't get the non tobacco rating, all insurance companies allow you to get a 30 day free look period. That means that if you aren't satisfied with your result you can apply to do a different company and test your luck on the free medical exam. I hope this answers your question :)