Martin,

I think that I either found a bug or am unclear on intent of the TransferResult output.

WinSCP v5.7.0.0
Win2k12R2
Using automation along with Tom Malkewitz's WinSCP Powershell Module (https://dotps1.github.io/WinSCP/)
SFTP transfer protocol

If i try and download a file, say /remotedir/remotefile[1].pdf, the TransferOperationResult.IsSuccess reports True, even though the file was not downloaded to the local location. If I escape that path using the escapefilemask, which makes the new path /remotedir/remotefile[[]1].pdf the download works as expected and the local file is named c:\localdir\localfile[1].pdf as expected.

That's correct (expected) behavior.

The localfile[1].pdf is a file mask (the [1] is a set pattern). If the mask matches no file, WinSCP won't transfer anything (and it's not an error). Note that localfile[1].pdf mask does not match the localfile[1].pdf file.

If you want to test that the transfer succeeded and something was actually transferred, test also TransferOperationResult.Transfers.Count > 0.