Sorry to hear about your friend but with the sort of naiivete that he displayed it seemed like he was just begging to get taken for a ride.
If you are running a business, whether it's selling real estate in paradise or selling ice cream cones in hell, you have to commit yourself to it and never take a day off.
If he was gone months at a time and was willing to share his profits 50/50 instead of paying the guy a regular bi-weekly salary, and left him an expense account with no accountability, does this sound like any way to run a business?
And this is'nt even taking into account that Sosua and Puerto Plata are havens for criminals on the run. He should have checked his background somehow. How did he come to trust this guy, anyway?-"I trust you because you speak my language and we drink the same beer, so here's some cash and the keys to the amusement park?" Is that how he thought it all out?
Maybe your friend is not cut out for the DR. There are other places in the world where bloated, elderly germans can get laid and drunk.
And yes, I may not speak his language but a least I'm trustworthy. And I can take german classes in Sosua, so whats' the big deal?