It likely is context or culture specific, but I have given presentations with my left hand at least partway in my pocket (thumb outside) while using a laser pointer/clicker in my right. There is a delicate balance between coming across as confident/relaxed and coming off as not being serious/professional enough. Heckling a speaker is never a good thing (unless the speaker really deserves it for the content of their presentation perhaps in extenuating circumstances, but not within an academic context certainly).

It is likely context or culture specific, but I have given presentations with my left hand at least partway in my pocket (thumb outside) while using a laser pointer/clicker in my right. There is a delicate balance between coming across as confident/relaxed and coming off as not being serious/professional enough. Heckling a speaker is never a good thing (unless the speaker really deserves it for the content of their presentation in extenuating circumstances, but certainly not within an academic context).