The world of science does not limit itself to one form of measuring deaths. It does not require a positive test, or for everyone with an opinion to be satisfied that the deaths were all 100% caused by Covid-19 as opposed to Covid-19 being somewhat involved.
There are a bunch of different versions of the death stats, and Scotland is no exception. Experts will look at both deaths where Covid-19 is mentioned on a death certificate, but also total excess mortality. Total excess mortality is not some weird unscientific bullshit, it is a well established thing that countries look at every winter to get a measure of the impact of things like influenza or a really bad winter.
In this case I do not even have to resort to total excess deaths to get a figure close to 2800. I can just use the data from last Wednesdays National Records of Scotland data.
National Records of Scotland
www.nrscotland.gov.uk
I realise you may decide to quibble on about how these arent all Covid-19 deaths, and indeed they choose their language carefully with the 'where COVID-19 was mentioned in the death certificate' bit. Anyway England & Wales do just the same thing, just not necessarily in the daily stats. But daily stats are only good for viewing the death trends with slightly less lag, when it comes to more accurate figures the ONS of England & Wales, NR of Scotland and NISRA of Northern Ireland are the established sources, just with more lag. So I do not intend to spend further time today dealing with your misguided angle.