Tie breaking in Otsu method
You need to add another criteria for the tie breaking. 

Maybe how coherent each threshold area is after the we apply the threshold. 

So for example lets say you have a tie between thresholds T1 and T2. You can apply T1 and than find the number of connected component C1 it gave you than apply T2 and find the number of connected component C2 it gave you and than decide to take the threshold that gave less connected components.