That's exactly what Putin wants. Firing on those supposed "native Crimean self defense forces that have nothing to do with Russia at all, really!" will give the Russians the evidence they'll play to show they're just there to protect people when they come in hard. It's a provocation and the Ukrainians aren't biting. Meanwhile, pressure builds on Putin because everyone can see he's lying about these troops, trashing that image as a democratic leader he tries so hard to project.
In the News/Activism forum, on a thread titled Russia reportedly seizes a Ukrainian military base, begins air drills in Crimea, Bubba Ho-Tep wrote:
Gutless Russians for not wear insignias and gutless Ukrainians for not firing a shot.
Some western agency should snatch a couple of these guys and find out if they belong to a regular Russian unit not some Crimean milita as Putin claims. Turn them over to the Ukrainians and then call for a UN meet and scream invasion.