Is Hynix an original RAM for iMac?

I bought an iMac in Houston Texas on september 2006, almost two years ago. I had some problems with it so I took it to a support office. When they gave it back to me, I opened the memory slot to put another RAM I had inside, ant I'm pretty sure the memory in it was NOT the original, but I can't remember like 150% sure. The RAM was Hynix brand. Question is...

Does this memory -Hynix, made in Korea- possibly be in an original iMac, or they don't use this brand on iMac original factories? If it's not, then I can be sure I was 'stolen' -or 'exchanged'- and the original iMac RAM being replaced for a crappy one instead of the one who came along with it when I bought it, brand new.

Does anyone know about this, or where can I find out? Is Hynix RAM supported and released in original iMacs?

Thanks in advance!