What fallacy is it when someone says "this is true/it happened, therefore there are good reasons for it"?

For example:

We drive of the left (or right, depending on country) side of the road, therefore there must be a good reason for it.

Assume, for the sake of argument, that both sides are an equally good choice.

The fallacy part is the claim that reasons exist when in reality they don't. The original event/fact is the result of an arbitrary decision. There were no "good reasons".

What fallacy is it when someone says "this is true/it happened, therefore there are good reasons for it"?

For example:

We drive on the left (or right, depending on country) side of the road, therefore there must be a good reason for it.

Assume, for the sake of argument, that both sides are an equally good choice.

The fallacy part is the claim that reasons exist when in reality they don't. The original event/fact is the result of an arbitrary decision. There were no "good reasons". 

What fallacy is when someone says "this is true/it happened, therefore there are good reasons for it"?

For example:

We drive of the left (or right, depending on country) side of the road, therefore there must be a good reason for it.

Assume, for the sake of argument, that both sides are an equally good choice.

The fallacy part is the claim, that reasons exists, when in reality they don't. The original event/fact is the result of an arbitrary decision. There were no "good reasons".

What fallacy is it when someone says "this is true/it happened, therefore there are good reasons for it"?

For example:

We drive of the left (or right, depending on country) side of the road, therefore there must be a good reason for it.

Assume, for the sake of argument, that both sides are an equally good choice.

The fallacy part is the claim that reasons exist when in reality they don't. The original event/fact is the result of an arbitrary decision. There were no "good reasons".