we watched it happen yesterday, the 405 tried squeezing down the inside into cascades and the 500 must not have seen him and turned in. Not too bad really, think the 405 came off worse, seemed to loose drive somehow hand had to be towed. The 500 did a few more laps, caught the back of the pack and overtook a few but then retired because the wheel tyre was catching the arch. Just a new quarter required i think.