This piece would appear to take place not too long after the crash, as they are still on the beach and Jack is still working to gather all the medical supplies together. Jack is going through a suitcase (probably not his own) when Ethan approaches and asks if he’s the doctor. He says that he’d heard that Jack was rounding up all the medicine and that he might want this.
Ethan opens up a whole suitcase full of different medicine and various other medical bits and pieces. Ethan says “there must have been a hypochondriac or something”. Jack asks him where he found it to which Ethan simply replies “out in the jungle”. What he probably meant was “from the huge stash of medical supplies at our little community in the middle of the island, where there is a bunch of us just waiting to invade your camp and abduct you and your people…”
Ethan then thanks Jack for organising things, having a little perspective, he says that everyone else is just waiting for rescue and that he thinks Jack is smart. Jack makes a comment that “its nice to know I’m not alone”, Ethan replies “your definitely not alone”.
During their conversation Ethan refers to Claire, mentioning that Jacks probably thinking that he’s going to have to deliver her baby on the island. Jack says that at least he’ll have someone to lend a hand, but Ethan goes quiet. As Ethan gets up to leave he stops and tells Jack that his wife had died during child birth, and that their baby didn’t survive either, which is obviously why he went quiet earlier.