Extra passive nodes activated after refunding

Playing a level 70 witchhunter I've noticed that when I refund several passive nodes(weapon set definitely, not sure about general), I am then able to spend more passive points than I refunded or have available. The lines between the nodes remain unlit, but the nodes themselves light up. Assuming it's not just a visual bug, it's nice to get free passives, but I guess it should still be fixed.