Sulu was crouching by Ianto's side by the time Jack showed up, he himself having been keeping an eye on his vitals as best he could with his training. When Jack came over to them, he didn't bother to move aside; Jack could have his own side of Ianto, after all.

He gave Jack a flat look, "It's not like I knew how bad off he was without him saying anything, and he sure as hell didn't clue me in. And what do you think happened? He got sick and passed out." Okay, maybe Sulu shouldn't have used that tone - he really shouldn't have, actually, because that always just got him in trouble with Jack, but. Jack was not his commanding officer (no matter what uniform he was wearing), and Sulu was rightly worried for Ianto's safety. A little harshness should have been expected from him. "I couldn't exactly drag him all the way back."