Unfortunately because he refused the test when symptomatic it can't be proven if he had caught it by then or not.
The list of symptoms attributed to long-covid is growing. My neighbour now has heart problems that were only diagnosed months later. They cannot say for sure if they are a direct result of covid. Some people have died at home without getting a test and medical attention.
There will be a large margin of error in both directions.
What about the people that cannot get the treatment for other serious medical conditions due to the pandemic? Many of those will die that could otherwise have been saved.
It's impossible to quantify exactly. It's also impossible to make accurate comparisons with the figures from other countries since even with the same basic reporting frameworks there will be differences in protocol.
We do know that it is causing a lot of deaths and that there are things we can do to try and reduce that.