Weird dates in thread

I just noticed the post dates in this thread.

Three years ago, then one year ago, then four years ago...  After that they go back to normal sequence.

From behind the scenes I can see that what is now one thread was originally at least three separate threads that have been merged. When we merge there is a temporary post saying something like 'original poster - I have merged your topic into this topic. I hope that helps' but they've long since vanished into the aethers, leaving traces only in the form of a messed up timeline.  

Dr Who would love to base a story on it, no doubt...

Maybe we need to put something in trello that in the case that posts are not in chronological order, there is a marker in the thread that says "threads were merged here"

??