Is one obligated to pay for these clothes in this situation?

It mostly depends on the purchase agreement. Was there an agreed delivery date? If so, there is no reason to pay again.

As long as he returns the clothes.

Maybe he needed them by a certain date, for an event, and so had to go out to the store and buy something.

@jca2 I think the implication is that he plans to keep the clothes.

It’s a question of ethics really; I don’t know that he’s obligated to pay for them or that they would come after him. But ethically, I think he should pay for them once received. If they are no longer needed by him, he should return them.

It is up to the shipping on how they want to approach this. On many items it costs more in shipping and reviewing returned items and restocking than just letting you keep it.

It is becoming more common to let you keep the items unless they are large ticket items.

This just happened to me on a 4 items.
Items were stated “lost in shipping” by the sender. They processed the order again without charging me again. I received both orders within a day of each other.
While the shipping organization did not raise a need to have me return the duplicate, I asked for a free shipping label and returned the duplicate items.

I’ve been in this situation a few times.

When it was a larger company, they said just to keep the item. It wasn’t worth the cost of shipping to return it. I usually end up donating the refunded item to a goodwill or local charity group.

When this happened with a smaller merchant on Etsy, I contacted them and repaid them with a discount.

I would pay for them.

Sometimes it is more convenient or less costly for a company to replace only than it would be to return-and-replace. Some factors that may go into such a decision would be customer satisfaction, cost of return and restock, cost to replace item, or many other variables.