offsetStroke not worked for one svg

[tolyanor]

Hi, man! Thank you for paperjs-offset lib, it's realy cool!
I have one svg:

offset working good for this:

But offsetStroke not working:

cl.offsetStroke(10, { cap: 'round' })

I have nothing in console and originally image on canvas. offsetStroke() working good with another my SVGs

Here is "wrong" svg
flash.zip