The story you mention is just that – a story. For one thing, tigers, like most predators, will happily eat carrion – if you’re a meat-eater and you come across a free meal just sitting there, it makes sense to eat it, since you haven’t had to expend any energy catching it for yourself. For another, a tiger can easily tell from your scent whether you are alive or not – playing dead would not fool it for a second. One explanation for a tiger leaving you alone if you “play dead” could be that, if you are lying down and not moving, you do not appear to be a threat, meaning the tiger has no reason to attack you. It won’t think you’re dead, but it won’t think you’re dangerous either, so might go on its way without bothering with you. Tigers, lions, leopards and other carnivores like bears, wolves and hyenas all happily eat carrion, even when it is in quite an advanced state of decay and/or has maggots crawling through it. Rotten meat is not harmful to them as it is to humans.