I was perusing the very first issue of Tradition (1.1, Fall 1958) and in doing so read a very interesting and very dated article called Halakchic Implications of the Dead Sea Scrolls by Sidney B. Hoenig (the article's byline says he was then Director of the Yeshiva University Department of Adult Education, as well as a professor of Jewish History--here's a no doubt partial bibliography of his scholarly writings).
In any event, after a brief overview of what the scrolls are, what non-Jewish scholars and theologians were then making of them, Hoenig asks many questions about them as they might pertain to Judaism. Assuming that many of the finds are older than the Mishna and the earliest rabbinic literature--they are as follows:
1) What to make of the presence of 23 biblical books and the apparent absence of one (Esther)? This leads to certain questions, such as: "Are we to conclude that Jews did not observe Purim in the Second Commonwealth, and that only "the Day of Nikanor," recorded in the Second Book of Maccabess was observed? Was Purim as a religious festival instituted only after Yabneh and Usha? Is the first actual reference to the reading of the Megillah that of R. Meir who wrote his own Megillah when in Asia Minor? We know it was R. Joshua ben Levi (3rd century) who prescribed that the Megillah be read at night. Was it practised before?" Since Esther does not include God's name, does its absence from the Qumran canon corroberate its singularity? Did Esther have no sanctity and was it included in the canon only due to popular request--כתבני לדורות (Megillah 7a)?
2) What of the order of parshiyot in our Tefillin as compared with tefillin found among the scrolls in the Judean Desert?
3) What of the non-massoretic biblical readings?
4) What of the scribal rules apparently violated by these scrolls, eg, crossing out mistakes rather than erasing them?
5) What of the calendar, which is found in the Jubilees Scroll? "Was the calendrical system now rediscovered...the authentic one...and our system only the result of R. Joshua and Rabban Gamaliel...?"
6) What about theology? For example, the Pesher Habbakuk speaks of a moreh tsedek who is to supplant the kohanim in the Temple.
7) If the Qumran scrolls are siphrei minim, are they worse than the apocryphal books, such as Ben Sira, which was revered by amoraim? Or ought they be destroyed (theoretically)?
In short, what are the implications of these scrolls?
Then, Hoenig shlugs up all the kashyas in one fell swoop:
Following the unique, ahem, eccentric view of Solomon Zeitlin at the time (which, come to think of it, was also endorsed by William Chomsky in his marvelous Hebrew language history "Hebrew: The Eternal Language") Hoenig says that the documents are not ancient, they are medieval, they are Karaite and they say nothing about Judaism.
"One recognizes that the Karaites were devoted to the Torah. חפישו באורייתא שפיר was their slogan. But they often copied biblical texts as they saw fit, sometimes agreeing with the masoretic text and at times introducing their own readings.* Carelessness and ignorance were also some of the outstanding qualities of these Karaitic scribes.** Purim, being a festival ordained by rabbinic dictum, not unlike Chanukah, may have been rejected by these biblically minded sectarians.*** The Tefillin, being מדאורייתא, on the other hand, may not have been different from those used by the Gaonim.**** All the discrepancies in the scrolls can be explained by this defection of the predecessors and followers of Anan, who hated Hillel and the Rabbanites and considered themselves followers of Shammai. Indeed, the pecularities of Halakhah among them, too, can be seen in their out-Shammaing Shammai.
"What we really possess in these scrolls are early Karaitic writings....The Torahs found in the Dead Sea Scrolls have no sanctity; we need not, therefore, be disturbed by any conclusions of halakhic import, for there are none..."
He then dismisses the option that a pre-rabbinic Judaism existed in Second Temple times.
"Maimonides' Ninth Principle remains true: "This Torah will not be changed nor will there be another Torah revealed by the Creator."
Needless to say I well understand how in 1958 Zeitlin's outsider view (that the scrolls were medieval and Karaitic) was seen as another valid scholarly point of view. So naturally there is nothing to be complained about Prof. Hoenig's adopting that view; he was persuaded by the evidence for that position, which we now know is entirely fantasy.
 Shlug means "beat" or "hit" in Yiddish and shlugs up is a yeshivish idiom for really trouncing an argument with good answers.
 Kashyas, questions.
*** No. Purim is biblical and that is important. Karaites indeed never celebrated Chanukah, since it is not from one of the 24 Bible books. But from the Karaitic point of view Purim isn't "מדרבנן," it's מדאורייתא--biblical--as it indeed is.
*** Hoenig means that tefillin matching Rabbenu Tam's order were found at Qumran. According to him this order is found in a responsum of Rav Hai Ge'on, meaning that Rashi supported the Eretz Yisrael order and Rabbenu Tam, the Ge'onic, or Babylonian order. But as Prof. Moshe Bernstein notes, tefillin of types in addition to Rashi and Rabbenu Tam were found. (Perhaps Hoenig did not know this, or the discoveries hadn't yet been made publich--he also doesn't mention Rashi tefillin.) In any case, Karaites do not and never did wear tefillin. It's דאורייתא status, noted by Hoenig involves accepting the rabbinic דרשה of the relevant verses which the Karaites do not do. Not impossible, if non-rabbinic groups at one point agreed with that דרשה, but in fact the Karaites never did.