[doug1001]

i suspect "smart alec" was chosen with exactly the intention you're expecting--ie, i'm not a native English speaker but i believe the term when used by adults to refer to other adults is benign--perhaps like the "G"-rated version of "wise-ass" or "pedant." Maybe wrong here, but benefit of the doubt perhaps....

[dang]

No, it's a putdown. This breaks the HN guideline against calling names in arguments (https://news.ycombinator.com/newsguidelines.html).

The account also has a history of being snarky.