That understanding is untrue, it was actually an internationally agreed upon tariff by the WTO. It has since been repealed though, so cameras built after 2019, or ones that have had a firmware update since then, no longer have the limit.
Your camera likely used a loophole to get around the required tariff. For example, the camera I have, a DC-G9, used to simply start recording to a new file at the end of the time limit. Now that the tariff has been repealed, it records to a single file. Likewise, for legal reasons your Nikon wasn’t recording an 18-hour livestream, instead it recorded 36 consecutive 30-minute livestreams, which wouldn’t be illegal.
That understanding is untrue, it was actually an internationally agreed upon tariff by the WTO. It has since been repealed though, so cameras built after 2019, or ones that have had a firmware update since then, no longer have the limit.
I’m going off my experience running an 18 hour livestream over HDMI with my 2015 Nikon dslr.
Your camera likely used a loophole to get around the required tariff. For example, the camera I have, a DC-G9, used to simply start recording to a new file at the end of the time limit. Now that the tariff has been repealed, it records to a single file. Likewise, for legal reasons your Nikon wasn’t recording an 18-hour livestream, instead it recorded 36 consecutive 30-minute livestreams, which wouldn’t be illegal.