Well, after a debug session using node-inspector, I managed to single out the piece of code on the Amazon page that throws that error.
It's a CSS rule inside a long inline <style>
element, that JSDom does not know how to handle:
<style type="text/css">
...
.cust-rec-aui-button @-moz-document url-prefix(){
.cust-rec-aui-button .a-button .a-button-text{
line-height:29px
}
.cust-rec-aui-button .a-button.a-button-small .a-button-text{
line-height:21px
}
}
...
</style>
At first, I thought it was a CSS syntax error (though JSDom is not supposed to throw an exception for those), but then I found some sources (here's one) that say this is perfectly legal.
So, after conferring with the developers of JSDom (see issue on Github to get the whole correspondence, along with code that reproduces the issue), it has been declared a bug, and hopefully will get fixed!