Is there a word that means "forced into somewhere despite not fitting"?

Solution 1:

You might make use of the following idiom:

Procrustean bed - "a scheme or pattern into which someone or something is arbitrarily forced" (Merriam-Webster)

Procrustes was a figure from Greek legend who cut or stretched his guests to fit his bed.

If you need it as a verb, you might use the construction: __ was made to fit the Proceustean bed of __.

Solution 2:

ram - to push or put (something) into a position or place by force. More importantly, it means to force passage or acceptance of.

Your example - I know we claimed this phenomenon could be described by theory X, but in retrospect we really just rammed our observations into theory X's model

wedge - to force. (someone or something) into a very small or narrow place (literally or figuratively)

And there is always drive.

Solution 3:

"I know we claimed this phenomenon could be described by theory X, but in retrospect we really just BLANKed our observations into theory X's model".

Retrofitted, (in which case change "in retrospect" to "in hindsight").

Retconned, (geeky, more suited to describing the ulterior politics of flexible official narratives and histories -- wouldn't be applicable to normal science, but might apply if a lab had become a real soap opera).

Adapted, (not slangy), altered, modified, mutated... choice depends on how one feels is about theory X.

Forced.

(Shoehorned is probably fine...)

Solution 4:

Actually, force is not a bad start. You could try "force fit," which is in abundant usage to mean something that is forced into a place or application where it just doesn't fit or belong.

Examples from Wordnik.com:

So rather than force-fit plans crafted for one part of the world onto another, Cisco created an entirely new geographic region devoted solely to emerging countries. Inder Sidhu: Decisions without Tradeoffs

...

What I ironically find more interesting is taking what few alternate “explanations” anti-evolution activists have offered - note how vague they are becoming in terms of “what happened when” - and trying to force-fit the evidence to see if any of those mutually contradictory alternate “explanations” has any merit. Accretionary lapilli - The Panda's Thumb

...

McCain is too complex a character to force-fit into the caricatures that ideologues at both extremes are always peddling as the “truth.” As Democrats Fight, McCain Seeks the Middle - The Caucus Blog - NYTimes.com

...

Examples abound. In fact, one hears this usage all the time. I'd say it's the perfect for you.