The videotape was already processed. It showed Ruiz and Jimmy at the corridor entrance all the way to their entrance into the underground bar hall. The footage after Ruiz entered the small room wasn't on the tape because that room had no surveillance. The testimony from that location was provided by the only person who survived inside the room and Ruiz in the hospital.
The clarity of the surveillance footage wasn't great. All you could see was Jimmy propping up against a high table without moving. Minutes later, Jimmy suddenly pulled out a Glock from his waist and shot at the two guards by the door. Then, he turned and hid behind a nearby pillar. Three people appeared from another side, and the footage showed Jimmy taking them down and then breaking into the small room to shoot two more people against the wall.
The second reel of videotape showed the same scene, but from a different angle and closer to Jimmy, revealing more details.