I don't think there is a right or wrong here. I just know that I'd probably do what your buddy says he would do. That's just my nature.
Both are wrong.
Turn it back on her in a playful way, not in a dickhole way that admits defeat and takes it out on her.
Something like "I don't know, we just met and you could be a total creeper. First you have my number, then you are chasing me down. A man must make sure he is safe". All done with a shit eating, sheepish, boyish grin.
How she replies to that tells you if you have a chance while telling her that you can be a bit of fun.
DD anyone? No not Dungeons and Dragons.
This is the correct response. I have used similar responses before three or four times, it's good fun, if you make her laugh, you feel great even if she never calls. It shows her you can take rejection (if she is rejecting you) and it shows her that you're funny and interesting (if she is on the fence, or really doesn't make a habit of giving out her number to complete strangers she met five minutes ago).
I don't know. I've never taken a girls number. I've always given mine out.
I am not sure you're right that it means, forget it. I agree it seems likely, but it's possible a woman has some other reason, such as: she only has a cell phone now, and she doesn't want people calling her while she's driving. Many people are protective of their cell #s, even if it's nothing to do with dating.
I agree they don't know for sure. That's called "mind reading" and it can lead to awkward misunderstandings. It's OK to guess but only keeping a sense of lack of certainty.
I see what you mean, but according to the sister in-laws that this is the new technique for for girls. its obviously not true all of the time, but at least 80% of the time in my experiences as of late, its a kind 'thanks but no thanks'