Anyone invest with a hard money lender (lend to them to get interest)?

[Jim Stanley]

I have twice invested $50k with my hard money lender's investment fund. 

I gave them $50k and they lent it out to flippers to make a profit and paid me interest on it.  It worked out fine, though each time I got a little less than advertised interest rate (about 9% vs 10%) and I had to send a reminder email to to get my money back, but I did get it back.

I ask about others' experience, because I'm still not 100% sure it's not a ponzi.  Sure they paid me both times, but that's exactly what a ponzi would do.

Thanks