Workaround and circumvent were my first thoughts.
Depending on context you might also consider loophole. For your quoted example, loophole works perfectly. "Our lawyer found a loophole to avoid the adoption laws."
: an error in the way a law, rule, or contract is written that makes it possible for some people to legally avoid obeying it
The above definition is a bit casual where, legally, the word loophole implies that there is still some questionable behavior.
What is LOOPHOLE?
Without violating its literal interpretation, an allowed legal interpretation or practice unintentionally ambiguous due to a textual exception, omission, or technical defect, evades or frustrates the intent of a contract, law, or rule.
Law Dictionary (Black's Law Dictionary)
Using a loophole, though legal, is still morally objectionable, because you "break the spirit of the law". If there is no such thing happening, I would use a different word.
Wikipedia has a dedicated article to the concept of a loophole.