Correctly identified that a product would be a GDPR problem. Said product's main feature was deanonymizing non-consenting visitors.

Insisted that certain metrics should be recorded, ended up identifying massive gaps in SLA, improved overall QoS.

Was asked to give SRE and Devops advice to a team. Told them to document their "regular tasks"; that is, to write down a doc "How to Upgrade Frob Databases" so that they would have a way to do all the "Upgrade Frob Database for Customer #xxx" tickets on their kanban board. Got pushback. Wrote the docs for them anyway. Their kanban board drained over the next two sprints.

Edit: In all cases, got massive pushback from management and never from devs nor engineers. Was called "arrogant", "troublemaker", "enabler", reprimanded, etc. You asked for examples, you get examples.