Perhaps the implication is not

"extra vigilant ... [compared to my level of vigilance on the happy path]",

but rather

"extra vigilant ... [compared to other people I work or have worked with]"

The latter is how I read it, because I have definitely worked on teams where the happy path was heavily scrutinised, but error handling was treated as an afterthought, and rarely inspected too closely, leading to anything from error strings copied from another part of the application with names not updated to match the new location to throwing XException but only handling YException, so the XException bubbles up to a much less useful handler.