Legally you have to have 1 working brake (don't quote me on it, I'm not a lawyer :p) so they don't recommend it but I don't think the law is enforced. I've been overtaken - and overtaken myself, thanks long downhills - by police cars and they sort of look and just ignore the fact you could quite easily kill someone or yourself if you were to crash. I've even spoke to police officers and they just tell you to be careful, but if someone wanted to take a large company to court for encouraging illegal activity (I guess that's how it's worded) then they would win so Dan's just needs to cover its ass =^,^=
I used to have working leg like you, then I took a stem to the knee.