AstraZeneca recently leaked sensitive credentials to GitHub, exposing patient data connected to their Salesforce cloud environment. The leak was caused by human error, specifically developers forgetting to ignore the exposure of developer credentials online and not updating it for over a year. This incident highlights the importance of secure secret management practices in development, as exposing secrets can lead to exploitation of systems. Developers can use methods such as gitignore files or secure secret managers like Hashicorp Vault, AWS Secret Manager, or GCP Secret Manager to avoid committing sensitive information to public repositories and protect their systems from potential threats.