Is this video 50p or 25p?
AVCHD Lite uses 25p/30p shooting rate and records it to 50p/60p container using frame doubling. Panasonic did that because, I presume, they were unable to shoot true 50p/60p at that time, on the other hand AVCHD and Blu-Ray specifications do not support 720p25 and 720p30 videos. Panasonic did this to stay compatible with the AVCHD format.

I guess the reason was that this way you can author the original clips as-is onto AVCHD Disc or Blu-Ray Disc, and they will be fully compliant and playable by standard Blu-Ray Player.

Nowadays a camera simply stores whatever it records in one of the standard containers like MP4, then you edit/author in whatever format you prefer. But ten years ago the compatibility between AVCHD and Blu-Ray was a selling point for both formats.