It's not unusual to get 10 or more in a single conversation. If you're running normal quests with people they pile up like mad, I don't know how you would only get 8 in a flashpoint.
I know that for each conversation option where you can get points, I have been getting 2/4 if in a 2 many group and 3/6 if in a 3 man group. I'm not certain if this goes up to 4/8 in a 4 man group, but it's possible, and each of those can happen multiple times in a conversation with an NPC.