The problem about asking directions in Mexico: people want to please you so much that they’ll say almost anything to avoid saying no, they don’t know. In fact, you pretty much just don’t say no here.
We norteamericanos see answering yes to save face and not to actual intent as a teeny stretch of the truth, just short of an out-and-out lie. The other side of the coin (which is not heads or tails but eagle or sun) is that when we – honestly, we think – give a straight-up no, it’s considered incredibly rude and brusque.