I can see there is a problem in that a volunteer has taken a new photo of a headstone that had previously been photographed AND transcribed. The volunteer has merged the new photo thus claiming credit for the transcription originally transcribed by the first volunteer. So now we have two transcribers claiming credit. I am not sure why credit should be given to another transcriber. All they did was take a photo and merge. There is more to transcribing than merging.
We have changed transcription to include all who help in the process. This gives credit to everyone.
If someone else already transcribed a stone that I also photographed I delete my photo if the first was better and transcribed correctly. BUT, if it was a poor photo or incorrectly transcribed the simple fix is to merge the transcription to both photos and make the corrections in the process. We both get credit. Someone who did it first and someone who corrected it. I think I read that this also allows for the GPS info to be gathered from two different devices for a more accurate location.