At least one source (Odeen Ishmael) states that the Dutch introduced rice as a farming crop to Guyana from seed imported from the US colonies, the Carolinas and Louisiana, specifically, as early as 1782.

As far as mastering it, it took quite a while for that to happen, with irregular water supplies, and other agricultural issues. The sedentary life of a rice farmer, who had to tend his crops, then made them prime targets for slave traders.

So it seems to be the other way around. The rice was introduced to Africa from the new world by Europeans, and those farmers that became good at it were enslaved and brought over.

There's an excellent book about exactly this subject called Black Rice which goes into the first cultivation of rice in South Carolina. It certainly does seem that the slaves brought their knowledge of rice growing with them. In fact, rice started as a slave subsistence crop in South Carolina before it became an exportable cash crop somewhere around 1700.

As far as your question goes, the honest answer is that we are not sure. There was contact between sub Saharan Africa and Asia before the age of exploration, but it was not direct by any means. There's also some subtle differences in the kind of rice grown in Africa and Asia.