1. Such discussions do not take place in front of a podium.
2. Answering reporters' questions is rarely "real life and death."
The teleprompter is a hard indicator that he is not prepared, to which being fairly up to speed on all current “hot” subjects is a major part of the job.
If this rube can’t come across well without prompting in a news conference he sure as hell will strike out in discussions with relative equals.