Sabotage attempt in Hong Kong

How did they really hope to score with this? Arent the stewards going to hear the things going off? and arent they going to find needles everywhere? ANd arent they going to notice horses getting wobbly? or not breaking right? I dont know how syndicates run but me thinks there might be easier ways to make money.

Could be more the work of a mad genius type who hadnt thought the whole thing through. Har!