This isn't true at all.

If any foreign buying stat looked single digit it was only because the metric was so broad so as to include areas where there was zero foreign buying interest.

The week the BC Liberals brought in the foreign buyer tax they had data in hand that showed foreign buying in Richmond and Burnaby was (going from memory here) between 15-20% of sales that period. Worth noting that at the time those areas were building lots of new builds so possible that the trend the government was concerned about was new build condo purchases being dominated by foreign capital. That's my speculation only. CoV proper I think was around 11%.

Globe and Mail articles on this issue from around 2016 call out some of the data and there are some startling numbers that make it clear why the government acted. Perhaps its available on some government website too I dunno.

They never started collecting actual citizenship/residency data on house sales until a year or two ago. I remember one analysis out of UBC that assume foreign owner if they has a "foreign sounding name".

From what I've seen, some neighborhoods are high, but it's at the margin. Canadians snorfing up massive amounts of debt in order to acquire more property is a bigger driver.

Yes around 2016 they finally started gathering real data and it was so remarkably high in certain areas they brought in the foreign buyer tax. It only took like a month of data before the government, which btw long dismissed that there was any problem, was convinced that there was a real problem.