The reason I like the Closable interface is that it allows to use the try/catch JDK 7 syntax if we need to. Also I have the feeling that every projects has its own CloseableIterator that are  basically a copy of the same thing.

Since the TupleIterator methods overrides the one in the interface removing the exception I tend to prefer this solution but if you think it can cause potential problem later on, It's ok for me to change it