Fridge Brilliance: Due to Trautman's Korean War service as stated in All There in the Manual, aside from his 'Nam service and Teasle's Korean War service, one has to think why Teasle has a better relationship with Trautman despite Trautman's Vietnam service (that Teasle dislikes in others like Rambo), is probably because Teasle saw Trautman as a fellow Korean War veteran kindred spirit to get along better than sole 'Nam vets.
Germans Love David Hasselhoff: The film was enormously successful in Turkey. In Istanbul, one of the major cinemas of the city showed this film for over 50 weeks, despite strong rivals such as Shogun playing at the same time.
Rambo's line of "In town, you're the law. Out here, it's me." In other words, he is the law.
According to the DVD's Survival Mode easter egg trivia, Teasle's resume in his profile included being a little league coach, which is funny as Teasle's actor Brian Dennehy would later voice baseball legend Babe Ruth (who in the climax gets told that it wasn't the Little League when letting the Kid Hero play in the World Series) in the animated children's film Everyone's Hero. Also, Dennehy would play a baseball coach in the 2001 sports comedy Summer Catch.
Other than Teasle, turns out the other obstacle that Rambo faces in the movie are rats. Interestingly, both Teasle's actor Brian Dennehy and the subject of rats would later being involved in the DisneyPixar animated movie Ratatouille with Dennehy voicing the rat pack leader Django.
Idiot Plot: The whole movie (and quite possibly the entire franchise) could've been avoided if a) Teasle didn't bother Rambo at all or b) Rambo just left the town at numerous points in the film.
Jerkass Woobie: In the DVD's director's commentary, Teasle is said to be this due to him having served in the Korean War, which has been forgotten and harbours prejudice and jealousy towards Rambo due to the Vietnam War being a hot topic at the time this film was set and the fact he was highly decorated more than Teasle himself (Rambo was awarded the Medal of Honor, while Teasle was awarded a Silver Star, Purple Heart and ADSC, which Teasle is implied to consider them inferior to the more well-regarded Medal of Honor). Even though he is genuinely grief-stricken at his so-called best friend Galt's death and wants to avenge him, he is completely oblivious that his friendship with him is absolutely one-sided due to Galt's despicable nature and even purposely ignoring Teasle at the time of his death. Also, despite being a somewhat loathsome antagonist, he's not really an evil villain, just a broken, misguided, angry soul and is rounded up as human and fallible. It's made more explicit in the novel with Teasle's Woobie status Up to Eleven, as novel reveals his wife had divorced him, worsening his angst, while it is also revealed that Teasle's father was killed in a hunting trip.
Make It Look Like an Accident: Maybe the helicopter pilot jerking the controls in just the right direction to send a seatbelt-less Galt falling out of the helicopter to his death was an accident. On the other hand, the helicopter pilot had already called Galt out for disobeying orders and shooting at an unarmed suspect. Galt responded to this by telling the helicopter pilot to shut up and fly steady or he'd kill him (basically making the pilot an accessory to murder). So when Rambo throws the rock and cracks the windshield...well, accidents do happen.
Memetic Mutation: NOTHING IS OVER! NOTHING! More specifically, Stallone's melodramatic and almost incomprehensible delivery of the whole speech.
Moral Event Horizon: Art Galt crosses it when he recklessly shoots at Rambo without giving a shit about his own safety or that of the rest of the police department and actually threatens to kill the chopper pilot if he doesn't fly the chopper right. Coupled with his Police Brutality towards Rambo back in jail, this cements Galt to be a definite Dirty Cop, perhaps more so then Teasle.
Narm: Sobbing Johnny Rambo recounts his traumatic 'Nam experience, (making even hardass Richard Crenna's lip tremble) is this if it's not a Tear Jerker; the enunciation leaves something to be desired, even if the circumstances note Rambo detailing how one of his best friends was blown apart by a bomb carried by a child and trying to find his legs can excuse it.
There's also David Caruso's screams of pain when he gets stabbed in the leg. This was immortalised in Golden Axe.
The part when the asshole deputy Art Galt dies has a bit of Fridge Humor: He's falling in slow motion but screaming at regular speed. So, does that mean he was squealing like a chipmunk on the way down? His screams also made it into Golden Axe, by the way.
Some Anvils Need to Be Dropped: Whatever you feel about war in general, antagonizing people who have gone through traumatizing experiences, e.g. a soldier who has lived through a war, can have disastrous consequences.
Teasle's motive behind his vendetta against Rambo for being a Vietnam vet, as the Vietnam War virtually erased the existence of Korean War vets in the public eye as well as his Jerkass Woobie status with more Pet the Dog moments should have been explored more like in the novel.
The plot of old-fashioned Korean War tactics versus modern Vietnam War guerrilla warfare (as it has been showcased in a few scenes like the climax's showdown part) could have been given a lot of depth to show contrasting military-training comparisons between veterans Rambo and Teasle.
Vindicated by History: The film received mixed reviews in 1982, but critical opinion of it has grown more favorable over the years when compared to its more actionized and less thematically-complex sequels.