Is there a particular reason why it became wiki when I posted it?
Yax, the answer's revision history shows that you made it Community Wiki yourself:
Post Made Community Wiki by Yax - occurred 21 mins ago
You can flag your answer for moderator attention, explain that it was made CW by mistake and ask for the CW status to be removed.
Just testing to see if you get any alert when mistakenly checking the "community wiki" box..
Nope - no alert at all so it might be good idea to post Feature Request asking to add such alert as this can't be undone and people tend to do mistakes.