If I was a betting man, I'd bet that he's in Malaysia. Someone like him would have swum across easily. From there, it's pretty much easy passage to Indonesia.
It's actually quite easy to get into and out of Singapore via smuggling routes. No kidding but I once knew an SG wanted man who would visit his parents here in SG during festive season. He would come in from the Malaysian side of our border and leave similarly. Then again this was a long time ago and perhaps the SG authorities have a better system intact.
What's really disapointing is the misinformation that has been provided. Now we hear that he doesn't really have a limp at all?????
My take is that he overpowered a guard and wore 'official clothing' when he got out. No one dressed inappropriately would have made it out. Either that or he hid in one of the laundry or garbage bins and was actually driven out unhindered.
It's a shame that the inquiry is not going to be an open inquiry because it would have been interesting to find out how he actually made it. Dang! This even beats Prison Break.