Nice, I knew there was a neat functional solution out there somewhere! To match my spec above:
~findIt2 = { |arr|
var sizes = arr.separate { |a, b| a.first != b.first }.collect { |a| a.size };
var indices = [0] ++ sizes.integrate.drop(-1);
var values = arr[indices];
[indices, sizes, values].flop.select { |a| a[1] > 1 }
};