Looking for insight into 1994 Mint practices ...

JustMakesCents

I am currently valuating a collection of a gentleman who recently passed. Among hoarding many items, he was an avid subscriber of mint issues (i.e. Proof Sets, Mint Sets, Proof Silver Eagles). Each year he bought two of each and kept them in the boxes they were shipped in. However, he is missing the 1994 Proof Silver Eagles, which are the highest-valued date outside of the 95-W. I also ordered mint issues for myself during that time frame and found a few years ago I was missing the 1994 Proof Silver Eagle and bought one on Ebay. Anybody know if there was something that happened that year that caused customers not to be notified of the Eagle's? Is this somehow related to the higher price on this date? Any help would be appreciated.

Thanks,
Jeff