Formally, you are right. You always apply one particular standard to a product. There are times however, when certification agencies will require additional requirements to be met, beyond that standard.
In one case that I recently had to deal with, the safety inspector from an accredited agency "pulled in" some additional requirements from 60950 into a device certified to 61010. The device is still formally tested to
61010 and that's what will be written in the report when it eventually passes, but the inspector insisted on some corrections (in this case: the addition of a fuse to a circuit to make it comply with the requirements for a "limited power source" per 60950) to the design.There's no direct reference to 60950, but the inspector considered it as required anyway, with the reasoning that the circuit in question was supplying power to a CPU board that has external (and not otherwise isolated) communication ports. So he applied parts of the standard for ITE to prominent "ITE parts" of what is otherwise test equipment.
Apparently there are variations in how inspectors do their jobs, and some work this way and others work that way. You may meet one, who looks at a device strictly from the perspective of one applicable standard, and then another time you may meet another, who will in addition dissect the EUT by function and "pull in" some additional requirements from standards where he considers them appropriate for the relevant part.
At the end, there is still one standard mentioned in the report however.
Regards Dimitrij