Just to add experiences with Lemon here, I'm remaining impartial on the "is he a scammer" front for now, but I will add to the best of my ability my experiences with him so far.

We have done 1 successful large BTC trade, he went first.

He says he is a lawyer, and I have employed him to do some legal work for me, however as yet the quality hasn't been up to par.
He told me he was going to send me client/lawyer agreement paperwork when I first requested his services on 18th of April, As of yet, despite multiple requests, the paperwork has still not arrived.

He was supposed to be sorting tax stuff out for me, he says that HMRC hasn't replied to him yet. In my experience, HMRC response times are far less than 2 months.

I have been having major issues with the banks, he hasn't been all that helpful with it at all.

I find myself having to contact another solicitor, because the work quite simply isn't up to par.