Etymonline offers this:
pickle mid-15c., probably from Middle Dutch pekel "pickle, brine," from a Low German root of uncertain origin or meaning (cf. [...] German pökel). [...] Figurative sense of "sorry plight" first recorded 1560s.
The Phrase Finder supplies some background:
The figurative version of the phrase, meaning simply 'in a fix' [...] arrives during the [16th] century. Thomas Tusser's Five Hundreth Pointes of Good Husbandrie, 1573, contains this useful advice:
Reape barlie with sickle, that lies in ill pickle.
[...]
There are a few references to ill pickles and this pickle etc. in print in the late 16th century, and Shakespeare was one of the first to use in a pickle, in The Tempest, 1610 [Act V, Scene 1, Line 2354]:
ALONSO:
And Trinculo is reeling ripe: where should they
Find this grand liquor that hath gilded 'em?
How camest thou in this pickle?
TRINCULO:
I have been in such a pickle since I
saw you last that, I fear me, will never out of
my bones: I shall not fear fly-blowing.
Follow the links for additional insight.
Dictionaries
The Shorter Slang Dictionary (1994) says:
hate (sb's) guts to dislike (sb) intensely. Adopted from the USA around 1937.
The New Partridge Dictionary of Slang and Unconventional English (2008) says:
guts noun 1 the stomach; the general area of the stomach and intestines. Standard English from late C14; slipped into unconventional usage early in C19 UK, 1393. 2 the essentials, the important part, the inner and real meaning UK, 1663.
And:
hate someone's guts to hate someone intensely UK, 1918
The Historical Dictionary of American Slang has a similar "I hate his intestines" from 1901, and according to chief editor Jonathan Lighter: "Guts being regarded in that far-off age as rather vulgar."
Antedating
I found a 1913 (and possibly 1912) antedating. Within The Law was a Broadway production in 1912, written by Bayard Veiller. Here's an extract from the 1913 book based on the play (plain text / full view) "by Marvin Dana from the play of Bayard Veiller":
"Was there any bad feeling between you and Eddie
Griggs?"
Garson's reply was explicit.
"Never till that very minute. Then, I learned the
truth about what he'd framed up with you." The speaker's
voice reverted to its former fierceness in recollection,
of the treachery of one whom he had trusted.
"He was a stool-pigeon, and I hated his guts! That's
all," he concluded, with brutal candor.
The same line appears in 1917 books of the script, and I expect it was also in the original production which was first performed at Eltinge Theatre, New York, September 11th 1912.
Via ADS-L is a 1911 found by Garson O'Toole:
[ref] 1911 June 3, Seattle Daily Times, Stenographic Report of Today's Testimony, Quote Page 8, Column 6, Seattle, Washington.(GenealogyBank)[/ref]
[Begin excerpt] You further said: "I hope I may never see my mother alive if I ever gave the ---- a cent. I never had use for him, and I hate his guts." [End excerpt]
(The dashes above represent a single long dash.)
Best Answer
My first instinct would be that this is quite an old expression, although it was likely used in a military or otherwise ranked and graded environment. It may be a bit more recent than I thought though. I found this link on quoteland.com where user thenostromo cites a source that is, alas, no longer available. It is however, archived by the WayBack Machine - thank you @DanBron for the link!:
So that would indicate an early '80's origin of the expression, making your '71 quote indeed anachronistic.
However, another user, Bobby Stafford, on the same page quotes from personal experience:
So, if you trust this person, the expression has at least been in use since 1966, albeit in a military context. Whether your '71 quote is an anachronism would then largely depend on the context in which it was used.