If I came across a road block, it is considered an offence to change my lane to go to another route?

Is a passenger required to check for oncoming vehicles before alighting from a car?

I’m a P-plater and was driving along Ang Mo Kio Ave 3 when I entered the wrong left turning lane at the cross junction and sort of panicked. Made a discretionary left turn on green and noticed pedestrians starting to cross the road. Thought I saw a bright white flash as I was turning left. Revisited the road earlier and didn’t see a red light camera, although there could be those CCTV looking cameras on tripods/poles. Do those cameras make a flash at such incidents and will I get demerit?

Navigation vehicle 3370 Ubon Ratchathani