Was Kirk really pally with the Klingons at the end of Star Trek V? That was also the same film he referred to them as "Klingon bastards."
It was originally in
The Search for Spock that he said that phrase in the singular, in reference to Kruge after he'd ordered David killed. Its use in ST V was no doubt just an attempt by the screenwriters to imitate the earlier film, and in context it's clearly a heat-of-the-moment thing when he thinks they're going to shoot at him. There was never any indication prior to ST VI that Kirk felt any particular bigotry toward the Klingons. Hatred for Kruge as an individual, yes, but there was no suggestion of a broader racial animosity, and the end of ST V definitely showed him having no problem being friendly with the Klingons.
Kirk's bigotry against the Klingons in ST VI was, no doubt about it, a huge retcon, and a difficult one to reconcile with everything we'd known about Kirk prior to that date. Looking back on it decades later, when people have grown up accepting TUC as part of the whole tapestry, it may seem like it fits in integrally with everything else, but trust me -- for those of us who were already Trek fans well before TUC and were seeing it for the first time, Kirk's racism against the Klingons was new, sudden, and unexpected. If you read the novels and comics that came out prior to TUC, the standard approach was to show Kirk as someone who had no particular animosity toward the Klingons and if anything was more open-minded than most about the possibilities of achieving peace and understanding with the Klingons -- even in stories that were set after David's death, such as the post-TFF comics published by DC. The idea of Kirk feeling hatred toward the Klingons as a race was totally new and fairly revisionist when TUC introduced it. It was difficult to reconcile with the character of Kirk as we'd come to know him prior to 1991. It was so awkwardly shoehorned into his characterization that when J. M. Dillard wrote the novelization, she invented a recent Klingon attack that had almost killed Carol Marcus, so as to provide some justification for this otherwise grossly out-of-character attitude on Kirk's part. Shatner himself was very uneasy with the idea of Kirk having such hatred toward the entire Klingon race -- in take after take of the "Let them die" scene, he tried to indicate that Kirk had second thoughts about the line the moment he said it. Because it simply did not fit the character of James T. Kirk.
And then there's the bit about in his log entry in Star Trek VI about "having never trusted the Klingons..."
Yes, in TUC, but the point is that evidence from prior films, particularly TFF, doesn't bear that out. It was a retcon that served the story. Remember, the people who made TUC were not the same people who made TFF. They had only one producer (Ralph Winter) in common and no writers or director in common. It's not like there's a single creative vision uniting them. The people who wrote TFF intended it to end with the suggestion of improved relations with the Klingons, but then the different people who came in and wrote/directed TUC decided it suited their story to start Kirk off in a place of deep hostility toward the Klingons, so they disregarded the ending of TFF and asserted as a retcon that Kirk had been extremely hostile toward Klingons as a race ever since his son was killed.