He didn't test the version of the extension that he'd built himself with 32-bit vscode, but the previous test with the prebuilt extension from VS Code Marketpla

He didn't test the version of the extension that he'd built himself with 32-bit vscode, but the previous test with the prebuilt extension from VS Code Marketplace which didn't reproduce the bug must have been done using the 32-bit version since that's what he had installed at that point in the tale.