Einstein imagined a man in a moving train who observed lightning which were on the same side of the track and at some distance from each other.
But try to modify the experiment. Let us imagine two men, say A and B. A is standing still on a platform and B is on a bike (whose speed can reach very close to the speed of light instantly). Both of them have their own stopwatch and both start it at the same time (which was the time when B started his ride). But imagine the lightning bolts on opposite side of the road. Since the road is not much broad, it would take same time for both the lights to reach A. But for B the situation might be different. Now let us say that B is driving the bike on the line passing through the midpoint of the road and towards the spot where lightning is about to happen. Suppose he started his journey and at $t = 1s$ the lightning event took place. Since the distance of B from both the lights is same (and he is very close to lightning spot at $t = 1s$), so he will also receive the lights of both the bolts simultaneously. And for both of them this event of lightning is simultaneous.
Note: take the distance of B from the lightning spot to be greater than c i.e. $3×10^8 m$.
So how can we say or prove time dilation in a moving frame or disprove simultaneity using this thought experiment? Am I wrong somewhere?
Avoid mathematical terms and give practical reasons only.
Picture is given below,