Well a barister might defend himself, but I guess if the case requires a barister, the prosecutor and judge may negotiate with the barister but not if its the defendent. Approach the bar ? The defendant won’t approach the bar…
The only thing in a lesser case, is that the magistrate or defendant may feel that the defendant has already answered a question fully , so when it comes time for the defense evidence, its left out ? its accidentally given unsworn , as argument, rather than sworn in as evidence ?
Or the defendant may use phrases he knows from reading law, and that makes his evidence sound like its made up from reading another case rather than the true story of his own case.
No, it’s about people who are attorneys. I wouldn’t dream of representing myself in any matter more serious than a traffic infraction. It’s (probably) not my field for one thing. For another, an attorney serves four roles, not just one: counselor, negotiator, advocate and evaluator. I can probably be an effective advocate for myself, but objective counselor? No. This applies in US system, but not so much in English/Welsh law because of the solicitor/barrister demarcation.
In one of the Perry Mason novels (written by Erle Stanley Gardner, himself a lawyer), the D.A. Hamilton Burger threatens to have Mason arrested, and Mason says he wants a lawyer. Burger says that’s ridiculous, and Mason says he’s not kidding, he wants someone impartial looking out for his interests.
As it turned out, Burger backed down, and we never learn (at least in that book, I haven’t read all of them) whom Mason would have called.
There have been a number of attorneys weigh in on the tread, and they all describe they talk about objectivity as the most important factor. See UltraVires’s post. UV is currently a practicing defense attorney.