You're watching what you want to watch. This is the full video from Justin Dunlap:
https://youtu.be/YhHbkMHsjW0?t=16 At the 20 second mark, you hear a hiss (someone sprayed mace, Dunlap moves closer and the cloud gets him opposite side of the street) but if you watch the YouTube video clock, the first round comes after the hiss but before the 21 second mark. 2nd round is fired before the 22 second mark. Simple video editing software will tell you the exact millisecond gap between the sounds, but that means the shooter already has his firearm drawn and at least at a low ready. There's no indication anywhere that the mace came from Danielson and his torso makes no rapid motion before the shots that would indicate raising a mace can and spraying unlike the shooter who made an abrupt change to shooting stance. At the end of the day, is being maced justification for deadly force? Especially when all logic points to the shooter approaching the victim with his firearm already drawn? Literally the only reason to bring the mace up is to use it as a mitigating factor to justify self-defense, when it fact the mace may have been Danielson's only chance at surviving after being approached by someone with a drawn firearm.
Sure is, and using mace as a mitigating factor for a murder is just one way of spinning an incident to fit a narrative.