Indeed, indicators such as trade volume can be used in logically contradictory ways. Nation states are not adopting protectionist policies, therefore there is no globalisation. Nation states are adopting protectionist policies, therefore there is globalisation. Globalisation means that nation states compete with all other nation states, and so trade increases and protectionism will be abandoned. Nation states are not adopting protectionist policies, therefore there is globalisation.
Nation states are adopting protectionist policies, therefore there is no globalisation.
If I find protectionism, I can use it as evidence, either way. If I don't find protectionism, I can use that negative finding as evidence - either way. Many apparently solid statistical indicators, can be used as evidence either way. International air traffic is growing, but so are regional airlines. Cultural evidence is equally double-sided.