[Fed]

Never heard of a 3 second or a 5 second rule.
It used to be blinker a 100 ft before a corner (30 M?) which I'd take as 30 M before changing lanes as well.

Never heard of "Lane change requires giving way to cars on your right" but not your left assuming it means cars in the lane to the right of you.
If you're changing lanes you have to give way to anyone in the lane you're moving into.

The witch has tried to out maneuver you but you left the gate open, put it down to a racing incident with no further action but if you ever hear from her insurance again totally deny any fault at all. You were already half way across the lane when she decided to turn one lane into two lanes, that's right isn't it?

Point to remember, this is changing lanes not merging.