It all started with Sam Mattis' crooked throw.
The American threw his discus into one of the poles of the throwing cage - and the net dropped.
It took the organizer a while to get the cage in order.
Once they got it, Swedish Simon Pettersson came forward and sent his discus over the net - out on the running track.
According to expert A Lennart Julin, the net in the cage was insanely low.
- It's absolutely incredible.
That is a cage you would use at the youth DM.
Now it is in a Diamond League competition.
You should not have to be afraid of throwing it out on the running track, he says in C More.
"Somewhat scary"
The net later went down again and the competitors were not impressed.
Not Julin either.
- This is a joke, he says.
Simon Pettersson downplayed the incident afterwards, but admitted that the throw out on the running track was nasty.
- That's what happens.
Just fun that something is happening.
But it was a little scary there.
Luckily no one was there, he tells C More.