That's a naive understanding of academia.

Meeting standards is nothing but a formality, a form to fill. The PhDs and lab staff doing the killing, if they have any qualms about the act itself or just the purpose of the killing, generally justify it away as being what they have to do to keep the job. The "humane" killing methods are learned on the job through trial and error, and such errors keep happening regularly to experienced staff.

Prior to lockdowns, many/most lab animals just got killed: interesting quality of life standard.

What's written in lab policies is not at all how it happens in reality.

that does not sound at all like my lab experience, nobody was doing ad hoc trial and error on basic animal management