Try this:

Set 'Positive Response' as default value for the 'customer response' and create only one after business rule as below:

 In the Advanced script add:

(function executeRule(current, previous /*null when async*/) {
var gr = new GlideRecord('asmt_metric_result');
 gr.addQuery('instance', current.instance);
 gr.query();
while(gr.next()){
gr.u_customer_response = 'negative'; // assuming your field name is 'u_customer_response' and value is negative for negative response
gr.update();
}
})(current, previous);