They are probably referring to medical gear at the early stages of COVID. China wouldn't export things they thought they would need even if there were contracts for items.

They also took it a step further and asked Chinese in other countries to get medical supplies back to China potentially leaving other countries in difficulty. E.g. https://www.smh.com.au/national/second-developer-flies-82-to...

It should be a wake up call for politicians, though no doubt will be forgotten. International trade is great and but this clearly showed nations should keep some base activity domestically for key/essential industries.