Agent Carter, when attempting to recover zodiac, fires her PPK sixteen times without reloading. A PPK can hold either 9 or 10 rounds. Impossible to fire that many times without reloading.
A henchman is able to get the drop on Agent Carter after a smoke grenade is deployed in a small room, because he has a gas mask on. However, smoke grenades are not incapacitating agents (like tear gas) so the mask would only help so much. In a small room like the one shown, the burning of the grenade would have removed a significant quantity of oxygen; gas masks are just filters and cannot help with lack of breathable air so the individual would still be disabled or unconscious.
The M18 smoke grenade Agent Carter pushes through the hole in the door is clearly a fake "airsoft" type consumer smoke grenade. The markings are the wrong size and use stencil font whereas real ones are screen or roller printed in thinner continuous letterforms. In real smoke grenades all the smoke comes out the top (fuse) end and the volume should be much, much higher; it would be impossible to see across the small room in which it was thrown, for several minutes even after opening the door.
The events portrayed in Marvel One-Shot: Agent Carter occurred one year after Captain America went into the ice, making it no later than 1946. There is a fallout shelter sign above the stairs to the SSR office where Agent Carter works, but the U.S. government created the design for the fallout shelter sign in 1961.