There’s a general principle in strata that, provided previous members of the committee and owners in general have acted in good faith, they can’t be held liable for decisions that later turn out to have been an error.
In theory, all owners are responsible for the decisions made by the committee, on the grounds that they collectively, could have overturned them at a general meeting.
It might be different if there was proof of some sort of corrupt behaviour from which individuals had benefitted, but even then it would be difficult to prove and pursue.
This is just one of those occasions when you have to put it down to experience and move on, a little poorer but slightly wiser.