If a text message is sent by someone while the chat log is being loaded, the new message is displayed before the log messages.
This bug can (only?) be reproduced by using http://quickgit.kde.org/index.php?p=scratch%2Fddomenichelli%2Fktp-paste-contact.git&a=summary
I see a relation to bug #317866.
Thank you for the bug report. As this report hasn't seen any changes in 5 years or more, we ask if you can please confirm that the issue still persists. If this bug is no longer persisting or relevant please change the status to resolved.
Dear user, unfortunately Telepathy is no longer maintained. Please migrate to another solution, e.g. for Jabber a possibility is Kaidan, for Matrix a candidate is NeoChat.