A learner can take the instructor by surprise by turning the wrong way or getting into the wrong lane. Learners can get flustered even with the most competent instructor and that road lay-out does look confusing. Without being able to hear the conversation inside the car you can't make any assumptions as to how much is down to poor instruction and how much is down to learner panic.
Nothing confusing about the road layout at all (other than everything is confusing to a learner, but it's not the learner that I have an issue with)
1: Junction with left turn only indicated and marked clearly with chevrons, onto a normal 2-way street
2: A right turn at a T-junction
Nothing out of the ordinary...the road with the tram lines isn't a one-way - the learner drifted over to the wrong side of the road (that happens, not blaming the learner, but if the instructor hadn't meant the right turn to be taken, then drifting over was plenty of notice that something would be awry.
Granted it's not clear on the video but at the beginning, the instructor was pointing to the right and pointing out the bus gate over to the right. Now, the conversation can't be "word for word" but would have been something like this starting from the first junction
"Now, see here - we want to be going right but the road is laid out specifically to stop this and we have to turn left. So, what we need to do is turn left here than turn right on the next road. Now, swing round in the road, that's it, now we can turn left and turn left again - don't worry about the blue bus gate signs, they haven't got cameras on this bus gate so you won't get done"
(No, I wasn't going to follow the U-turn and film further but as I progressed through the traffic lights and looked right, I could see "Jango" coming out of the bus gate - the whole point of all this was to get through the prohibited bus gate)
The "fuss" isn't claiming a "near miss" or some other dramatic incident, it is with learners being taught to ignore prohibitions and drive in bus/cycle lanes that they are banned from. I don't happen to consider it a very good grounding at all.