I prefer to think that common group etiquette is well known, but Its the context of the situation that is more important. An overgeared group has no need for a tank in a HM flashpoint, and it is often just easier to let the dps burn everything down, and the healer heal as needed.
Nobody should be having a go at a tank not holding agro in a hardmode flashpoint with everyone burning through in 61's. If a healer in 61's can't keep up dps in a boarding party, thats the healers problem, not the tanks or dps.
These conflicts seem to be focused around the group finder, where you have overgeared players blended with players in gear that the content is balanced for. In a situation where either the healer or the dps are in tionese, then the pace of the flashpoint should be set to accomodate them.
The heroic in question was on Taris. Not high level over geared players. When I group on my 50 I rarely run into situations where we can't burn everything down before it becomes a problem though, but my Commando is dps spec BH geared. My Vanguard is Tank, lower level and geared in blue armorings and mods for her level.