Recover Lost Voice Recording on EVO 4G
So I only tried to replicate the issue for a few minutes but even when I got the recorder to stop recording (opening the camera app forced the recorder to stop) it saved the recording.  I'm not sure if you already looked on the SD card but if you haven't try using ES File Explorer (or other file explorer) and go to "sdcard/My Documents/My Recordings" ... thats where I found my recordings. Maybe its still there.