CDC is estimating that a little less than 40% of the excess deaths in the past few weeks were not caused by COVID-19: https://www.cdc.gov/nchs/nvss/vsrr/covid19/excess_deaths.htm
> These deaths could represent misclassified COVID-19 deaths, or potentially could be indirectly related to COVID-19 (e.g., deaths from other causes occurring in the context of health care shortages or overburdened health care systems).
That is not saying "those deaths were not caused by COVID-19". They explicitly mention that these could be misclassified.
https://www.washingtonpost.com/health/patients-with-heart-at...
https://boston.cbslocal.com/2020/05/04/coronavirus-covid-19-...
https://www.nydailynews.com/coronavirus/ny-coronavirus-queen...