It seems to me that "a friction" is a legitimate, though unusual expression. It certainly has appeared, alone or in various form of modification, for many years, starting not later than the late 1700s, as the following examples document.
From an unidentified article in The Universal Magazine (September 1763) [combined snippets]:
As this demonstration suits all the points of the obstacle, it follows, that a wave reflected by some obstacle has the same figure on this side the obstacle, as it would have beyond it, the obstacle being removed. If the obstacle is inclined to the horizon, the water rises against the obstacle, and afterwards falls from it, and undergoes a friction, which occasions the motion, whereby the wave was reflected, to be put out of order, and very often even intirely destroyed : Whence it comes to pass, that the greater part of the time the banks of rivers do not reflect the waves.
From the entry for "BORER" in The Complete Farmer: Or, a General Dictionary of Husbandry, fifth edition (1807):
The toughest iron is the best for making this instrument, which should be well hammered, till its surface is quite smooth and even ; for the least roughness and inequality would occasion a friction, which would greatly retard its working. For the same reason, and also to increase the force of its fall, it is necessary that it should be perfectly straight; nor should it ever be struck with a mallet, hammer, &c. to force it down, because a blow might bend it, and it would easily break afterwards.
The same wording of this passage appears in multiple versions of this dictionary between 1793 and 1825; so if the included indefinite article was a typo, it was a long-lived one.
From remarks by Mr. Courtenay on the occasion of Mr. Abbot's being chosen speaker of Parliament (February 10, 1802), in The Parliamentary History of England from the Earliest Period to the Year 1803, volume 36 (1820):
This objection was, however, easily to be got over, for the gentleman now proposed for the chair would, with perhaps equal ability, fill that high ministerial office; for great offices had a wonderful power in bringing out latent talents, which even the possessors did not dream that they possessed, until thus placed in an eminent station. There was a certain friction connected with a great place, that elicited a blaze of abilities equal, if not superior, to the office itself. Besides, the office of Speaker disentangled the mind from all the shackles of partiality ; the practice of that impartiality begot a principle which made a man stifle even his private wishes ; and if he afterwards passed into a greater situation, he carried that principle of impartiality along with him.
More-recent publications that refer to "a friction" as a quasi-countable noun are not hard to find either. Here are four examples.
From C.S. Lewis, Christian Behaviour (1943):
Every moral rule is there to prevent a breakdown, or a strain, or a friction, in the running of that machine. That is why these rules at first seem to be constantly interfering with our natural inclinations.
From Dame Alicia Marakova, Marakova Remembers (1986) [combined snippets:
Sometimes, later in my career, and often today, I have sensed a friction between opera and ballet, with ballet feeling it is being treated as the Cinderella of an opera house. But when I joined Diaghilev in 1925, we enjoyed and respected opera and it was an accepted fact that the company should do so.
From Jan Veenstra, Magic and Divination at the Courts of Burgundy and France: Text and Context (1998):
Essentially critiques of superstition hinge on a friction between philosophy and theology, on a scientifically minded attempt to distinguish sense and nonsense and a religiously oriented attack on the presumed evil and wickedness of superstition.
And from Mary Colwell, John Muir: The Scotsman Who Saved America's Wild Places (2007) [quoted text not shown in snippet window]:
It [clearing Western land as part of a pioneer family] did, however, raise serious questions in his young mind that stayed with him throughout his life. Torment would be too strong a word, but certainly it produced a friction that he would forever try to soothe. the tension between what religion taught and how it was lived, between what people wanted and what they had to destroy to get it, and between keeping wilderness wild yet inviting all to partake of its pleasures — all these dichotomies tore at his mind and heart.
I think that all of these examples—and the original poster's example, too—are simply instances of elision, where "a friction" functions as a shortened form of "a form of friction" or "a type of friction" or "a variety of friction." This shortening is not at all unusual in English.
Editors tend to reject such formulations (when they notice them), but if the resulting expressions are immediately comprehensible—as I think they are—opposing them on grounds that they break fixed rules governing countable and uncountable nouns is less a matter of standing up for clarity and plain meaning than of enforcing inflexible rules on a highly flexible subject: literary style.
When writers give uncountable nouns a degree of countability—or at least particularity—in their work, do they show a lack of discipline or (less countably) lack of discipline? Or do they show neither? I'm not inclined to support blanket (or a blanket) condemnation of the use of "a" before any of a multitude of words and phrases that are not obviously countable.