While the article is slightly ambiguous about whether he only changed the oil every 20 000 km, or just that his receipts only verify every 20 000 km and he had it changed more frequently, something is weird here.
"After getting the recall notice, Lingard submitted his receipts to Hyundai Canada. It rejected the claim, saying his first engine failure was due to "insufficient engine maintenance, not the recall" because Lingard didn't do sufficiently frequent oil changes prior to 100,000 kilometres of driving, and didn't provide receipts for subsequent changes.
The company says he changed his oil every 20,000 kilometres instead of every 12,000 as required by the manual. After the warranty expired, Lingard says he stopped going to the dealership for oil changes. "
The implication, if I'm reading it correctly, is that during the warranty he took it to the dealer for oil changes every 20 000 km. Then he stopped taking it to the dealer, presumably (though unverified) took it elsewhere, and couldn't produce receipts. The fact that at no point does he claim otherwise makes me think this is true.
Assuming my interpretation of the article is accurate, denying coverage makes sense. He didn't stick to the manufacturer OCI in the time he had it serviced at the dealer, then had unverifiable service history after that. I wouldn't expect him to be able to produce every receipt, but it seems like the record at the dealer indicates he was already not having the oil changed soon enough.
The article is ambiguous enough that it's hard to understand the whole situation here.