The lines do seem to coincide with the two brightest yellow flares/fireworks in the pics.
Anyhow, do keep that photo as proof and try to reproduce a few more perhaps with bright lamps in a dark room as proof to the service and support. You might need those shots as proof (keep copies for yourself too) to prove your issue to the service technician otherwise they might just keep your camera for a week to a month and then return to you telling nothing's wrong or "it's normal" (my actual experience with Olympus support with a similar issue).
