SRE doesn't own the code. They own the system reliability. Devs are still responsible for writing the functional code.
Certain aspects of the release process may fall under SRE's purview, but what the tool does is ultimately the responsibility of developers (and product). The SRE book covers testing in one chapter (17), and most of that chapter is about production testing.
The question you need to ask is "is the system still within in SLOs?" If so, SRE is doing their job. If you think that resulted in a bad experience, change the SLO. But I'd ask what the heck kind of SLO would have prevented this issue?
