No, they did not start with a UBI. RMI was means tested from the start.
The RSA was a reform intended to "smooth the edges". While you would lose you're RMI as soon as you start working, now you can keep part of the RSA during a transition period.
But the problem with RSA is that it's really complex and most people still don't get it. And it's a lot of paperware for a relatively small amount of money.
I think France is actually one of the best place to start a real UBI scheme. Our system is close to UBI but probably the worst implementation possible, with a lot of edge cases.
This proposal details a complete reform of our tax system around a UBI: http://www.allocationuniverselle.com/doc/BIEN_Munich_2012-09...
Read the article again. His point is that the RMI (RSA) is what they ended up with, even though they wanted (started with) something similar to UBI.