Umpire Erasmus loves to surprise Jonathan Trott looks at his bat after being controversially given out LBW on the first ball during England's second innings at Trent Bridge. SOUTH African cricket umpire Marais Erasmus loves surprising people. Start up a conversation with him and within minutes the conversation will turn to rugby, which he played for Boland. "So," he will say, sticking out his barrel chest, "what position do you think I played?" Tighthead, comes the automatic reply. A shake of the head. Hooker, perhaps? Another shake of the head and he wearies of the game. No, five-eighth. But if that causes eyebrows to jump in surprise, it is of nothing compared to the reaction to his two critical decisions on day two of the Trent Bridge Test, first not giving Ashton Agar out stumped when on six - he went on to score 98 - and then, even more, his over-rule of umpire Aleem Dar to give out Jonathan Trott first delivery lbw to a Mitchell Starc ball that the batsman and all of England insist he hit. When the realisation dawned that Erasmus overturned Dar's ruling without the benefit of Hot Spot, which was in playback mode, still analysing Joe Root's caught behind dismissal off the previous delivery, surprise quickly gave way to indignation and, in turn, to outrage. "It was staggeringly bad - unbelievable," former England captain turned Sky Sports commentator Bob Willis said of the Trott decision. As for Erasmus's ruling that some part of Agar's left boot was behind the line when England keeper Matt Prior removed the bails, Willis again was forthright in his comments. "A shocking decision," he thundered. Still, Erasmus did take a dozen looks at the stumping and couldn't find conclusive evidence that the 19-year-old Australian actually was out of his ground, so why there was such outrage at a batsman being given the benefit of the doubt is difficult to fathom. But it was a different matter entirely with the Trott dismissal. Dar, in the face of the loudest Australian shout so far in this Test, stood his ground and ruled against the lbw appeal. Given that the ball would have taken middle stump out of the ground, there can only have been one explanation for the umpire's ruling, an inside edge. The Australians immediately challenged the decision but, in the absence of any side-on Hot Spot footage, which would have established whether ball hit pad before bat or vice versa, the expectation was that Erasmus would defer to Dar's judgement from 22 yards away. Instead, based on slo-mo footage which suggested the ball hit bat and pad virtually simultaneously, he sent down the word to Dar to change the decision and give Trott out. Dar, who had been watching the replays on the big screen, could barely disguise his disgust at the overturn, which raises the intriguing question of whether an umpire can be fined for dissent. Nonetheless, he did as he was told, sent a demonstrably disgruntled Trott on his brooding way and suddenly England, which a couple of hours earlier had looked in total command, found itself 2-11 and still trailing by 54 runs. England coach Andy Flower demanded an explanation from the International Cricket Council as to why Erasmus had deviated so dramatically from protocols and received, in quick order, an apology from chief executive David Richardson. And for good measure, the inventor of Hot Spot, Warren Brennan, also apologised for the operator error that led to the system not being re-set in time to record to Trott delivery. As for Erasmus, he was staying silent, although in the official Test programme he did make this intriguing comment: "If I'm not noticed, it means I have got things right!"