Batsmen have been a protected species since WG Grace grew facial hair and even with the advent of the DRS and all its over-stepping, ball-tracking and hotspot components, they seem to get the benefit of the doubt.
The ball hasn't changed while batsmen have added extra layers of protective padding and armour which allow them to change their batting techniques. Laws protect the willow-wielders - or whatever hi-tech blade they now use - because they can't be out lbw if a ball pitches outside leg.
Even if a delivery pitches in line and satisfies 123 other details, half the ball has to be hitting the stumps to send the batman back to the hutch.
After Dar's original decision was reviewed, the third umpire concurred the ball would have clipped leg stump and Smith had his departure card signalled again.
It was a brave call because Smith had moved down the pitch a step and then a further stutter before the ball beat his awkward defensive jab. Usually there is no appeal, certainly in Australia and especially at the WACA because of the bounce in the wicket. Dar thought the line was good and the delivery hit Smith low enough to clean out the woodwork. DRS concurred.
The repeat on-yer- bike digit from Dar provoked significant consternation from the Australian-laden commentary team, including the greatest leggie of them all, Shane Warne, who wants the DRS rules amended so 40 per cent of the ball has to be hitting the stumps.
If a ball is going to strike the stumps, then the batsman should be out. He's made a mistake and the bowler has won. That's how the game works.
If Warne wants to dilute decisions because he is not convinced about the accuracy of the DRS system, then the scheme should be altered.
For some time, these admittedly dodgy eyes have struggled to accept the path that ball tracker suggests deliveries will take after they have struck a batsman on the pads. The deviation in both direction and height does not seem to fit with the original line, swing, cut or spin of the delivery.
DRS is a substantial help for detecting faint edges, no balls, run outs, stumpings or where a ball pitches but it seems to still be a pin the tail on the donkey exercise when it comes to assessing bounce and all-tracking line.