Avatax bug report: error message outputting incorrectly

I was debugging an issue in the Avatax Woocommerce extension where when we validate the shipping address, it was outputting any error message twice to both the shipping and billing sections.

In reviewing their JS code, it is outputting the error after ALL instances of the class .wc_avatax_validate_address (e.g. after the shipping and billing buttons), rather than just the button you clicked (in our case, shipping). The issue is on line 126 of their JS.

Not sure how else to report this.

Thanks
Greg