The garbage posts you saw are being posted at a VERY high rate. Most of them are actually rejected, but some of them are getting through. The point is apparently to make this whole web server inaccessible from the traffic - and they managed to succeed a few times.

I hate doing this, but I'm going to make this board "needs to be logged in to post" hoping that it makes the DDoS eventually give up because they can't get through.

You can create an account easily, but if you want me to make you one, email me.