It's not always the case. But sending a witness questions in advance: a) increases the odds you can nail them for perjury and b) takes away the opportunity to s

It's not always the case. But sending a witness questions in advance: a) increases the odds you can nail them for perjury and b) takes away the opportunity to say "I haven't been briefed on this and I'll get back to you later." This came up about 10 minutes ago with FBI director Mueller's Judiciary appearance as well. Chaffetz wanted to nail him on geolocation surveillance and sent questions in advance, and Mueller said he ignored his aides and didn't read the briefing. Bad form.