How recover files from USB drive that Etcher started flashing? (Stopped at ~5%)

[SGSeattle]

• Ether 1.5.122 running on Windows 10. Runs as expected.
• Restarted a flash effort that had failed (had stepped away so UAC approval dialog or Etcher timed out.)
• Unfortunately it did not flash the drive I previously specified ("E"), instead if flashed the default selection ("F")!!
• I forgot about this quirk and selected to proceed, so started flashing the wrong USB stick. Stopped at ~5% into the process.

So:

1. Think Etcher should not select a target device by default - user should always have to choose which target to write to.
2. Is there a way to recover some of the data on the USB stick, if the flashing process had only barely started?
   (Am trying the TestDisk utility, but so far no luck.)
   Thanks