There may also have been other factors not easily seen from the viewing side of things. Maybe an alternative enclosure was being rebuilt or worked on, maybe there was an emergency with the cage the frogs were usually in, maybe the keepers are trying something new with regards to who inhabits what territory or space in the enclosure. The zoo knows what's going on behind the scenes, we don't, and it's unfair to bash on their practices if the frogs look healthy and act normally....which I'm betting they are at least still eating and fat looking. Same with the cane toad; while we may consider that less than ideal, I'm sure after a couple years, if the toad was too stressed, it would have stopped feeding or otherwise exhibited that somehow. If after a couple years it is still happily coexisting with an anaconda...well, clearly, the toad really doesn't mind that much.
No, it may not be ideal, but the suggestion to write to them and ask about it, rather than complain on a forum, is more reasonable and understanding of the fact that we don't know everything that they have going on, and can't know if there was a completely valid reason they were housing the animals like that.
-Jen