The law of small numbers is that there are not enough small numbers for all of the tasks that are assigned to them. That makes some math cranks find patterns which are really only caused by not enough small numbers around. One such crank kept finding the number 57 in events related to the American Revolutionary war. The fallacy is that if you look hard enough ANY number would work.
At the LLL workshop it was noted that LLL stands for both Local Lovasz Lemma (my wife asked ``an entire workshop about a lemma?'') or the Lensta-Lenstra-Lovasz algorithm. Here we see that there aren't quite enough sequences of letters, hence some get used twice. Of course in this case it helps that Lovasz is brilliant.
The only other example I now of two well known theorems with the same initials of authors is AKS:
AKS primality testing: Agrawal-Kayal-Sazena test of primality in poly time
AKS sorting network: Ajtai-Komlos-Szemeredi O(log n) sorting network.
AKS primality gets 13,500 hits
AKS sorting network gets 39,100 hits
Are there other pairs of well known results where the initials are the same?
(This may depend on what you call ``well known'')
When someone says AKS do you think primality or sorting network?
It may depend on your age and your field. I think of the Ajtai-Komlos-Szemeredi upper bound R(3,k) \le O(k^2/log(k)). I tend to NOT count that as another collision of initials since its the exact same authors as the other paper.