There’s been a sizable backlash over the grammar police attack on the phrase “one of the only.” Two emails in defense of the phrase:

“One of the only ____a grammatical mistake only by ukase, if there is a rule to this effect. It is not a logical error. It is used where “only,” an adjective despite its form, modifies a plural noun. Hence, any number modifying the prepositional phrase, “of the only ______ [insert plural noun]” refers to a plural object, and hence is a perfectly proper equivalent of “One of the few.” The proof of this can be seen by substituting a different number for “one” in the phrase I use as an example, such as “Two of the only surviving claimants to the Russian throne,” or “Three of the Twins’ only starting pitchers.” The objection to using “One of the only” is the logical objection that “only” derives from “one,” and therefore there should not be more than one member of a class modified by only (one can’t properly say “There is one men in the room.”) But “only” has come too far from its roots in the word “one” for this to be a proper objection. If it were a proper objection, then “only” could not modify a plural noun, and it obviously can (“Only women may apply.”)

And..

Jonah,
You were not mistaken! “One of the only” should be considered grammatically correct.
For example:
It is grammatically correct to say, “The only ones who knew about the money were Bill, Chris, and Mike.”
Thus, it is perfectly reasonable to say, “Mike was one of the only ones who knew about the money.”
The mistake made by the overly-hasty grammar hawk here is probably to think that “only” must refer to a single item or substantive, whereas in fact it may refer to several. However, the injunction against using “one of the only” is common enough that one may want to avoid it just to keep from arousing the ire of the grammar police.
Watch out for the grammar police, who sometimes prefer to spout rules than to think about these things a little bit.