If they advertise ability to record at 1080p and it's possible to push the hardware to 4K, that's not lying.

This is not any different than an ISP selling a 10 Mbps plan when gigabit is available.

Are they? Sure, the hardware is capable of x, but if you want to save money by having software limit it to x/2, how is that a lie? And before the "but they didn't tell me!" argument, we may care on HN, but 99% of consumers don't care whether a limit is hardware-enforced or software-enforced, and probably 80% of consumers couldn't tell the difference if they had to.