SMS Backup (and other similar apps), why is it saving messages in the wrong order?

[AC Question]

SMS Backup (and other similar apps) save messages in wrong order

I want to keep an archive copy of one conversation in particular, and I found a few apps that save it to xml format, which I can then open in Excel. The problem is that when I open this xml file, the messages appear in a wrong order. For example, if the conversation goes like this:

Friend -> Me: msg 1
Me -> F: msg 2
F -> M: msg 3
F -> M: msg 4
M -> F: msg 5

The messages will appear in the xml like this:

msg 1
msg 2
msg 5
msg 3
msg 4

I have no idea what causes this, I've tried at least 2 different apps and both of them do this. Any ideas on how to fix this?