Another person on PS4 reported this problem, but the crash was not reproducible with the current live game version or with the upcoming patch version (no ETA yet, just early in the new year).
When you re-tried the fight, did you vary your tactics a bit, to see if that might make a difference?
Please email supportdos@larian.com, with a brief descriptions and couple saves, one immediately before killing Evelyn and one before the start of the fight. You would first need to transfer the saves to a USB flash drive to get them onto a computer: in the Saved Data in System Storage section of the Settings menu, click Copy to USB Storage Device, select the relevant save(s) and Copy. From there you can copy it to email or upload to Dropbox or Google drive, etc, and provide a link.
