Really? I am surprised

I am certainly no expert, but I thought resident aliens spouse does not enjoy unlimited spousal transfer, but they at least are afforded 5 million estate tax exemption.  I thought the 60K estate tax exemption is only for non-resident aliens.  

http://martinwrenlaw.com/wordpress/understand-how-different-estate-tax-rules-apply-to-non-u-s-citizens/
http://www.sgrlaw.com/resources/newsletters/trusts_estates_trends/trustsnestatestrends_winter11/1622/

Again, I am no estate lawyer, but 60K exemption for green card holder just sound odd.