It's not game-breaking, but it feels very much like a bug. When selecting the target for the paladin's Cover ability, it's offset by one (as in, I have to click on the Fighter to cover the Rogue, or on the Rogue to cover the Caster). It's easy to compensate for, but it's definitely odd.
Also, if the Rogue is first on the turn order (might also apply to the others, but haven't checked yet), free actions (changing class, using an Instant ability) end the turn.