Maybe it's because Chris lost more than Levi, or self growth (it's because Chris lost more than Levi), but Chris doesn't really feel like being shitty behind wards is a good response to this.

"I haven't shit talked people behind their backs since I been here. I'm not gonna start doing it now just because the need to be a piece of shit is so strong I can't resist the temptation. He just called us pieces of shit, threatened your spot on the team, took my -" Chris stops himself to scowl at Levi. "I'm not gonna prove his disappointment right by becoming a worse person than I already am. I'm not a fucking disappointment, and I'm gonna prove it." It's hard to tell if Chris actually learned his lesson, or if he's currently combating a severe inferiority complex, but at least he seems determined.