I doubt it, considering the hurdles one must jump through to get a loan in the first place. Before one gets fully approved the property has to be appraised, inspected, and pass a title check. You would have been fully involved in this process, if you were on that title.
When we get a loan to buy a house, we personally never see that big money. That money exchanges through businesses. (Buyers lender to sellers lender, for example). So, I'm not sure what motive one would have for trying.
I get random calls like that too. I lived in an apartment last year and had a similar call that left me laughing. It's more than likely a random telemarketer that has a call list, randomly trying to get people to either take out a mortgage through their company or refinance one they have. It's all about the money they could potentially make by advertising their services.
I've never thought about changing my security question answers to the wrong ones. Great idea. I'm going to change mine now.