I think Pin has a valid point.
Having watched crews go through a SID briefing, it's not something you want to do when lined-up. Had the controller indicated that there was no immediate inbounds that would ease the pressure on the crew to complete the briefing, even then the presence of further pending departures behind Pin's a/c could easily result in the SID briefing being rushed.
This is the kind of scenario often encountered in CHIRP.