So maybe better to just invest unleveraged.

A lender would have to be a fool to lend on collateral that wasn't protected - if the house is lost in a fire or whatever, the loan is unsecured at that point and is basically credit card debt. 

His note seemed to indicate it was an unsecured line of credit so I wouldn't touch that with a 10-foot pole.The short answer is: everything is negotiable.  

@Joe S.I would say BP does a good job as well as its membersFor example when peerstreet went under people were on BP blasting them because “they did not know” they invested in unsecured debt because they noted they invested in secured loansBut if you read the literature it was clear the investors were unsecured even though the company invested in secured loans (which this structure is not uncommon) - they were called out for this.There are components related to communication that cannot be verified unless posted but most documents and property transfers (like the one I assume is referenced in the start of this post) cannot be disputed.

In my experience, underwriting single family home rentals in California typically results in sub-4% unleveraged returns, which is awful given the alternatives. 

Looking for unsecured loans/ credit lines to use for six months to a year.

The fact that this sponsor used investor money to gamble on high yield unsecured notes leaves a bad taste in my mouth.  

assumed that hard/private money loans were either unsecured or collateralized against non-real estate.

So at that point you have an unsecured note and your recourse is to sue on the note if they wont pay.. and or sue for fraud if they never gave your security but inticed you to make this loan saying there would be security.. so as to not throw your borrower under the bus here you may not be fully aware of what deal you actually made.hope this helps giving you next step but if its a significant amount of money I would get a consult with a RE attorney.

@Jay HinrichsThat lender yes made a very bad investment which I am being kind with those wordsI have a non performing loan in BK and a person gave this person $60k loan unsecured while they were in bankruptcy and never even ran credit or checked on his backgroundShe now wants to sue for fraud which great your suing someone in bankruptcy - the money is gone.