Capt. Sheridan would not be in command of a situation where his daughter was a hostage, and Romano's insubordination to the Lieutenant would result in his being removed from the scene.
A child who is supposed to be moments away from death unless she gets to the operating room immediately would not be on a regular patient floor. She would have been in the ICU with at least several IV lines, an arterial line, a central venous pressure line and possibly a ventilator. Likewise, after her surgery she would not be returned immediately to the medical floor without any medical equipment any where in sight.
While it appeared at one point that Romano was struck on the right temple, the scene showing that was while he was facing in a mirror at the bar. Accordingly, but the rest of the episode his left temple is bandaged.
Two significant police procedural errors take place- Hooker does not radio ahead to the hospital after learning of the threat until several minutes later, by which point it is too late. Next, Stacy hears the gunshot and runs into the hallway unarmed, then runs back to get her purse, presumably to retrieve a weapon. While her incompetence could be justified due to her being a rookie, Hooker as a seasoned officer had no excuse. Stacy also had several opportunities for hand to hand combat to disarm the weaker brother, something the recruits were shown being taught at the academy.