To clarify, are you asking about RMA'ing a processor with bent pins or one that you fried?
If you are asking about RMA'ing a processor that your motherboard fried, then that is entirely your responsibility. If you bought both the motherboard and processor from the same place and just bought them, you can probably get them to take them both back. But if you have had the motherboard for a while, and the motherboard fried the processor that is not the fault or responsibility of the company that sold you the processor. If they sold you a working processor and you trashed it, that should be your money down the drain.
Personally, if when I received the processor it had bent pins I would throw a fit and get it RMA'd. If it arrived with bent pins, then either they shipped you a defective part to begin with or they did not package it properly. Either way it is their responsibility. Now if you bent the pins by not holding the chip down when pulling down the lever on the socket, that is your responsibility. It is pretty clear when that happens, because nearly all the pins are bent or all the pins on one of the ends is bent.
IANAL, but there are laws that require for example:
TITLE 15 - COMMERCE AND TRADE
CHAPTER 50 - CONSUMER PRODUCT WARRANTIES
-HEAD-
Sec. 2304. Federal minimum standards for warranties
-STATUTE-
(a) Remedies under written warranty; duration of implied warranty;
exclusion or limitation on consequential damages for breach of
written or implied warranty; election of refund or replacement
In order for a warrantor warranting a consumer product by means
of a written warranty to meet the Federal minimum standards for
warranty -
(1) such warrantor must as a minimum remedy such consumer
product within a reasonable time and without charge, in the case
of a defect, malfunction, or failure to conform with such written
warranty;
(2) notwithstanding section 2308(b) of this title, such
warrantor may not impose any limitation on the duration of any
implied warranty on the product;
(3) such warrantor may not exclude or limit consequential
damages for breach of any written or implied warranty on such
product, unless such exclusion or limitation conspicuously
appears on the face of the warranty; and
(4) if the product (or a component part thereof) contains a
defect or malfunction after a reasonable number of attempts by
the warrantor to remedy defects or malfunctions in such product,
such warrantor must permit the consumer to elect either a refund
for, or replacement without charge of, such product or part (as
the case may be). The Commission may by rule specify for
purposes of this paragraph, what constitutes a reasonable number
of attempts to remedy particular kinds of defects or malfunctions
under different circumstances. If the warrantor replaces a
component part of a consumer product, such replacement shall
include installing the part in the product without charge.
Unless I'm reading that wrong, Federal Law says that they must replace within a reasonable time and without charge a defect or malfunction. I would consider bent pins a defect as the processor does not perform its intended purpose without having to be repaired.
[SNIP]
(2) Notwithstanding paragraph (1), a warrantor may require, as a
condition to replacement of, or refund for, any consumer product
under subsection (a) of this section, that such consumer product
shall be made available to the warrantor free and clear of liens
and other encumbrances, except as otherwise provided by rule or
order of the Commission in cases in which such a requirement would
not be practicable.
They can have you pay for shipping it back to them.
The performance of the duties under subsection (a) of this
section shall not be required of the warrantor if he can show that
the defect, malfunction, or failure of any warranted consumer
product to conform with a written warranty, was caused by damage
(not resulting from defect or malfunction) while in the possession
of the consumer, or unreasonable use (including failure to provide
reasonable and necessary maintenance).
They may try to claim the above. But the burden of proof lies on them, they have to prove that you caused the damage. If the processor has bent pins it will be difficult for them to prove that it was you who bent the pins and not them when they packaged it or in transit. If the processor is fried, it is a lot easier for them to say that they only ship new processors and the only way the processor could have been fried is for you to have done it. Both AMD and Intel have very good QA and it quite rare for them to ship a bad processor (I believe the number is around 99.97% good).
That said, I have straightened pins many times and it's been a long time since I've broken one, but it does happen, especially if the pins are bent a lot. As long as the pin doesn't break it's not too big of a deal. As long as the pin makes a good cold solder with the socket, that is all that is important.