Should you exercise extreme caution in this situation?

In the video you are driving in the left lane of a dual carriageway and overtaking a yellow bus travelling in the right lane. You must exercise particular caution. The answer is: yes.

The Road Traffic Act requires a driver who is overtaking to exercise particular caution, and especially to keep a safe distance from the vehicle being overtaken; before overtaking, the driver must also make sure that they have sufficient visibility and space, that the driver behind them has not started overtaking, and that the driver in front of them has not signalled an intention to overtake, change direction or change lanes. Overtaking a bus needs special attention for several reasons: it is long, so you drive next to it for longer; it hides the whole right side of the road from you; its driver has a large blind spot and may move into the left lane to go around an obstacle or to prepare for a turn; the blast of air behind a large vehicle can jolt a small car. So you keep lateral clearance, you do not slow down next to the bus and you do not stay in its blind spot, and you return to the right lane only when you can see the bus in your interior mirror. Particular caution means being ready to react immediately, not just "being careful".

Legal basis: Art. 24 para. 1 and 2 and Art. 2 point 22 of the Road Traffic Act (Prawo o ruchu drogowym)