Murder
Garrus was relieved that Shepard was back after the mission on Aratoht. She'd been gone for 2 two days, supposedly sedated by Dr. Kenson. The woman had been indoctrinated by Object Rho no doubt. She wanted to let the Reapers through the Alpha Relay. Shepard of course had to stop her.
Shepard explained she awoke with less than an hour before the Reapers were supposed to arrive. She had no choice but to activate the Project and send the asteroid into the Mass Relay. And unfortunately, in doing so, she wiped out the entire Bahak system. Approximately 300,000 batarians lost their lives.
And Shepard was responsible for it. But Garrus wouldn't let anybody hurt. He'd protect her and keep her safe because she was important to him. He cared about her and wanted her to know that.
