Investment Proposals Advice

[Account Closed]

Recently I had sent an Investment Proposal for an off market property to a local HML. The Lender expressed interest and thought the investment fit one of his programs. Everything seemed to be going as normal until after I presented the Lender with the Investment Proposal. My numbers were good and there was approximately $80K in net profits. Well, I never heard back from this Lender (strange) and now the property has been contracted by another rehabber. Needless to say, I had that funny feeling and have not made any subsequent Investment Proposals with that person. I know there could be simple explanations and I'm not asking for a list of those. My question is this, If I present a lender an Investment Proposal how do I know that the lender will operate ethically with my opportunity and not show it to other investors? Should I send a NDA before the proposal? Would the lender even sign it??