I think that the "reputation" of tiger sals not breeding in captivity is based on the fact that thousands of people keep these animals in aquariums or terrariums in their home, but there has never been a documented case of tigers breeding in this kind of situation. If they did breed indoors, there would be occasional stories coming out in the forums, and I haven't seen any.
To the best of my knowledge, successful "captive" breeding of tigers seems to require outdoor enclosures. I've read some indications that water depth is a critical factor. Since tigers often use vernal pools, this makes sense, as they would be wasting their energy to lay eggs in shallow water.
I have heard from Ed K. that A. opacum has been bred indoors in simple setups.