Continuity mistake: Ms Perkins fires her 1st shot into the 1st pane of glass, the second shot into the middle of the middle pane of glass. When the shot changes to John rolling off the bed, there are 3 holes in the glass before she fires her 3rd round. (00:55:50)
Continuity mistake: After the fight with Ms Perkins, John grabs her under her chin and puts his gun to her head. Camera changes to her saying "f**k you" and now his hand is on her ear. (00:57:50)
Revealing mistake: In the compound shootout there is one shot of John hiding behind a SUV, with bullets hitting all up the side of the truck. Look at the glass to see 2 explosive patches that turn into bullet holes. (01:02:35)
Continuity mistake: In the compound shootout, the one SUV gets riddled with bullets including a very distinctive double bullethole in one of the door pillars. This unique damage disappears a few shots later. (01:02:40)
Continuity mistake: The SUV that rams into John in the compound changes from a Ford to Chevrolet. (01:03:00)
Continuity mistake: Once John has been knocked to the floor in the compound scene, he has his hand next to his face. Camera changes and it's further away. (01:03:50)
Revealing mistake: When John is sent flying in the compound it's clear to see that John is replaced by a stuntman. (01:04:00)
Continuity mistake: When John goes on the short rampage with the assault rifle we see one of the henchmen climb into an SUV and floor it. It's clear by the hubcaps and rear of the SUV that it's a Ford Expedition, but the vehicle that hits the SUV into john is a Chevy Tahoe. (01:04:00)
Revealing mistake: When John finds Marcus dead on the floor, you can see Marcus is still breathing. (01:20:50)
Continuity mistake: At the end, John pulls out alongside the two trucks. Camera changes and now he's back in a single line behind the trucks. (01:22:34)
Continuity mistake: When John is chasing the SUV's at the end, he is level with them, then a distance behind them instantly. (01:23:00)
Continuity mistake: When Viggo crashes into John's Charger, it's bent out of shape pretty badly, almost to what would be halfway to the driver's seat. Yet John is fine, and in the next shot, the car is basically too. (01:25:50)
Revealing mistake: When Viggo pushes the car off the edge and it hits the ground, as it rolls you can see that the engine/transmission, drive shift and tank have been removed. (01:26:00)
Continuity mistake: At the end, John pulls the knife out of his side and it's got blood on it. Camera shows him starting to thrust the knife into Viggo and the blood has disappeared. (01:27:40)
Continuity mistake: When Viggo dies, he's sat upright. As the camera changes he's now slouched over. (01:29:25)
Continuity mistake: When John's friend enters the room where he is killed he removes his sport coat. When he is tortured and sitting in a chair, his coat is back on.
Continuity mistake: In the night club, when John is fighting the last guy before leaving, the guy throws John, he lands on his back, and has no gun/holster in his waist band on his back. A few seconds later a small pistol and holder appears and he takes it out and shoots at the other guy.
Revealing mistake: When John enters the airport to practice his driving skills, and is driving down the parking lot next to the taxiway - right as he makes his very first 180° turn to skid his car around, looking closely you can see the front tires never turn. It is impossible to intentionally skid a car to do a 180 without turning the front tires. Yet he does exactly that.
Revealing mistake: During the home invasion scene, the final guy is stabbed by John. On the 2nd and 3rd stabs the knife can be seen to flex slightly as John hits it.
Answer: No. Regardless of any cancellation that Viggo made after-the-fact, the "Cardinal Rule" still applies to Marcus. He accepted the contract, he was contractually-obligated to kill John Wick, and he failed to kill John Wick. Marcus broke his word, essentially, which was an inexcusable violation.
Charles Miller