A strange case of a deleted comment

I admit that this is a strange case, but if it can be fixed, I guess it should be. Perhaps a half an hour ago I went to my other recent post. At the bottom I saw a comment. I started to reply to it, but then I noticed out of the corner of my eye that a more pressing comment was above. I wrote a lengthy reply to that person and hit "reply". It went through okay. At the bottom I noticed that the original comment that I had started was still there. I thought, "That's convenient," and finished it, and hit "reply". The problem is that it didn't make a new comment. It replaced the lengthy comment I had just made above. Very frustrating.