Assistant racehorse trainer Leung Wai-tak was bound and robbed in his Sha Tin home yesterday by two masked, well-dressed men armed with beef knives. Also tied up and robbed was a technician who had gone to Leung's eighth-floor flat at Racecourse Villa to fix the television. Leung, 43, is assistant to trainer Ricky P. F. Yiu. It is believed the door of Leung's flat was not properly closed when the two men, wearing suits, stormed in shortly after 1 pm. The robbers escaped with bankcards, three Rolex watches, and a gold chain with a jade Buddha pendant believed to be valued at more than $100,000.