This is Poe's law territory, e.g. a lot of your own comments sound very similar to the parent, and there are other emoticons more commonly used to indicate sarcasm/joke.
Heh, I think that's possibly the only virtue to sarcasm: it confuses the pedants. I use friendly smileys or the word "heh" when I'm trying to be jovial, and I'm willing to give that poster the benefit of the doubt. :-)
> a lot of your own comments sound very similar to the parent
Which comments?
> there are other emoticons more commonly used to indicate sarcasm/joke
I think any common standard about something like this probably only applies to a narrow clique.
It also had a smiley in it. I'm pretty sure you missed the joke and don't realize you're preaching to the choir.