Robbie McKewen makes this same argument here.
“What was most disturbing to me was that when Fabio Jakobsen hit the barriers, he didn’t deflect back into the road. He went straight through them. That’s really poor planning, not just from the organisers themselves but the UCI, and they have to take responsibility for that. This is something that has been going on for years. I lobbied for it when I was racing, and I’ve been retired for eight years.
"I put forward a barrier design to both the UCI and the ASO at the same time, for exactly the circumstances like this. While things have improved at some races, a good barrier set-up has to be solid, it can’t come apart, and it’s got to be heavy. The board on the front of the barrier also has to come down at an angle and meet the road. Everything has to deflect the rider back onto the road.
"The barriers in Poland flew every which way, and it looked to me like they were made of plastic.“