In formal English the use of brackets indicates an insertion into the document by the author of that document. As reporting developed, we had for many years the use of only a typewriter, which did not have brackets as an option. We used parens instead. Now that brackets are an option, it is probably best to switch over to brackets for the insertion of things like [sic].
For the blurbs that signal events within the proceedings, the parens should continue to be used.
(The record was read.)
(A discussion was held off the record.)
…It was right in this area (indicating).