"Ready to defer"? It sounded more like Ro believed her own combination of commissioned rank and command-colored uniform ought to make her the queen of the hill, until O'Brien insisted that Troi's higher rank trumped everything else. Which probably wasn't formally true or anything, but O'Brien apparently didn't want Ro running things.
Ro: "We need to start emergency procedures. Who's the duty officer?"
O'Brien: "Lieutenant Monroe was in command, but she's dead. I believe Counsellor Troi is the senior officer on the deck."
Ro (incredulous): "Counsellor Troi?"
O'Brien: "She carries the rank of Lieutenant Commander."
Troi (quickly interjecting): "I'd appreciate some suggestions."
After this exchange, Ro makes all sorts of suggestions, which O'Brien counters with those of his own, and Troi then shoots down with her cleverly formulated "orders" (which are more like suggestions). Ro seems to be making a point of not directly addressing Troi at all; it is only towards the very end that she deigns to address the superior officer as "Sir" (rather than the derogatory "Counselor"), while O'Brien is always eager to formally honor the Lieutenant Commander and support her "decisions".
This is actually one of the more intriguing and enjoyable cases of the writers making use of the ranks and relative hierarchical status of the characters; O'Brien fits right in as the formal underdog who nevertheless gets to pull all the strings.