We've got our engineers on this one. It's looking like a quirky Google error, rather than something we did weirdly. Yay? I don't know if that's good or bad, really.
Good news for you, though! There's an alternative fix that will let you keep pagespeed on Just put this in your wp-config.php file:
define( 'CONCATENATE_SCRIPTS', false );
That tells Google to step back just a little on the JS issue.