Watch the video carefully. DFlash2's tool call fails on python syntax.
Usually models in this class nail things like that 1 shot, which the other side did.
I don't know the cause. It may be nothing. But I'd like to see the model doing something where its path is a bit more constrained, to help out rule out such oddities.
DFlash is lossless so this would be a bug in the implementation if it is indeed a regression against the target model.