Safety is relative. Sadly, many tourists have not done enough research nor do they have enough travel experience to make prudent decisions when they travel internationally and venture away from the relatively safety of their resort and the tourist activities that are geared towards entertaining these people and keeping them safe.
Everyday, tourists become victims of petty crime here in the DR and all over the world. Pickpockets are common in Europe and here in the DR, muggings, robberies and even the big one, murder from time to time. The DR being a developing country, with a questionable police force and even more questionable political will to tell the truth, can be a place where it is very easy to get in over your head without some experienced person keeping an eye on you.
You can have a safe "off the beaten path" vacation here. Staying on your resort is also no guarantee of complete safety. Traipsing about the country on your own is best left to those with sufficient travel experience to be considered street smart in a foreign country, a good health insurance policy and fundamentally, the ability to communicate with the locals when things don't go as planned.
A corrupt and potentially dangerous third world country is not the place for the inexperienced to stretch their wings and learn the ropes. Things can go wrong very quickly and getting out of trouble is always much more difficult than it was getting into trouble.
Hope your friend has a good vacation. You know them, I don't, so you have to be the judge of their experience and coping abilities. When asked, I tend not to advise people that they are guaranteed to be safe doing such and such or going to specific places on their own as I have no way to justify that statement other than playing the odds like everyone else.
