Sometimes, as a web developer, you have no consistent way to diagnose these issues. We found an issue using drag and drop uploads on one of our sites where if

Sometimes, as a web developer, you have no consistent way to diagnose these issues. We found an issue using drag and drop uploads on one of our sites where if you uploaded the same image in chrome, one after another, it would crash. So I wouldn't give all the flak to the developer, as it might be chrome.