This is probably too late to help you now, but maybe someone else can use this information in the future...
To add to what Andrew said, 7.1.3 Infrastructure states that the (b) Equipment shall be maintained to ensure the infrastructure necessary for the operations of the process. How can the company ensure that the rigging will function properly, if it hasn't been checked at its regular intervals?
Another point in the ISO is 8.4 Control of Externally provided processes, product and services. The service that was hired to check on the rigging failed to do their job, but your company failed to make sure that they did their job (shall determine the controls to be applied to externally provided processes, products and services).
A good PREVENTIVE measure could be to set up regular communications with your contracted services. This could be regularly scheduled phone calls, or emails. something to keep the communication open and the issue in the forefront of your processes. We also set up outlook monthly reminders to make sure that we are hitting our goals.