In this situation, are you obliged to stop, even if this would mean rapid braking?

As a general rule, a yellow signal prohibits entering the area beyond the signal, but the regulations provide an exception. As seen in the video, the vehicle is so close to the signal that stopping would require sudden braking. In such a situation, to avoid creating a hazard in traffic, the driver is not obliged to stop and may continue driving. This is stated in § 95 para. 1 pt. 2 of the Regulation on road signs and signals.