Long story short, history, profile data, and personal settings will remain even though the battery has been removed. Nitrogen loading, oxygen loading, and time settings will be lost, thus, the no-fly time will also be lost. The manual does not explicitly say whether or not the Err condition resets upon battery removal.
I would venture to say, however, that the Err condition will remain as they do have a method of retaining data when the battery is removed. However, since Err is a timer based function, and the timers seem to be reset upon battery removal, then it is possible that Err does reset. If Suunto really wanted to prevent liabilities, they would have thought of this tactic.
If you're looking for a computer that won't lock despite deco violations, the Zeagle Status II is what you want. It simply never locks.