On throwing alligators through windows

The suggestion of 'to infenestrate' ('infenestration', etc.) is based on a surprising terminological confusion, given Underhill's obviously finegrained understanding of the meaning of 'de-' in the original coinage. That is, 'de-' was used in the sense of 'down from' for the original coinage of 'defenestration', although the definition has since become muddled by a persistent confusion with 'out of'. Hence, Underhill's suppositional analysis of 'defenestration' is pretty much spot on:

But de- can also mean “down,” as in “descend” or “depress,” and I suppose the downward sense is the most important one here.

(From Lowering the Bar, 'Is an Alligator a “Deadly Weapon”?', by Kevin Underhill. Emphasis mine.)

However, for an associated term with a parallel or opposite kinetic trajectory, it would've been more pertinent for Underhill to observe that modern and contemporary uses of 'defenestrate' do suggest the original coinage is now a misnomer...the more accurate term, in that it would more closely conform to the intended meaning, is perfenestrate, that is, the verb meaning

to throw something or somebody through a window.

Although from my lowly perspective any flinging of alligators whatsoever is, indeed, an uphill battle, the case cited by Underhill emphasizes throwing through. The alligator was thrown through the drive-up window, and it was passage through the window that resulted in the particular charge of assault with a deadly weapon. If the alligator had snagged on the window of the vehicle in passage and fallen back into the vehicle, or if the thrower had failed to reach his objective by, for example, bouncing the alligator off the establishment and back into the vehicle, or onto the drive-through lane, the charge would of necessity have been attempted assault with a deadly weapon (supposing such an offense were chargeable in Florida).

So, the alligator in question went through not one, but two windows: the window of the vehicle and the drive-up window. Its trajectory upward or downward in passage is not "the most important [sense] here". Rather, the passage through (both) windows is the salient sense. In fact, the relative positions of the vehicle and drive-up windows are not detailed in any of the sources given; the alligator may have been thrown down through or up through the vehicle's window, and may subsequently, for all we know, have traveled down through or up through the drive-up window. Where the alligator landed after its passage through the windows, on a counter or on the floor, is also unspecified.