What happened to a lawyer that defended actually guilty client? ?

They keep doing their job.  

they defend to the best of their ability.  that's the job.  if you can't handle it, join the prosecutor's office and try to put possibly innocent people in jail

Lawyers LOVE guilty clients. They can charge them more.  Besides, the lawyer's job is to get the best deal for their client.  If that means getting 10 years in prison instead of 20, then that's the job.

It is a violation of lawyer ethics to "bail out" just because the client is guilty. But it's okay to bail out if the client doesn't pay. Does that tell you where a lawyers real interest is?

A lawyer must defend the client vigorously. If their is a conflict they can request a change of council, but not at risk to the clients defense. 

For instance they cannot say to the judge or other parties that they think the client is guilty during the process of representing the client, nor after, until a judgement has been made and appeals exhausted. That would create potential bias.

Just look at the OJ case. There is your answer