ye u cant lock drama
that said pretty unlikely this was lagging uour server. usually anyone trying to join a non portforwarded server and cant join end up spamming a bunch of this unintentonally due to the automatic repeated attempts to connect
the only time ive ever seen this used to actually ddos a server was when i had metario do it to my server as a joke - he had to write a script and open multiple clients and fully connect to actually pull it off though