The Congo has been producing tin at current rates for at least the last decade, the ROHS directive won't change anything there. The current black market can't expand to cover the extra tin requirements and still be a back door operation.
In fact we've been getting most of our Coltan (columbite-tantalite) from there for years for all our Tant capacitors. It's the demand from us that hs caused the current situation.
On the positive side the DCR is sorting itself out, and should be holding it's first free elections later on this year.