Here's a question I got recently: What happens to the legal system when the US suffers a Soviet style collapse? Answer: It will rapidly decay.
Here's a simple formula for this (it works for both legal systems and government bureaucracies):
Low legitimacy + slashed operating budgets = rampant corruption
Regardless of any decay in the legal system, business will still be conducted. Small disputes will be resolved through the existing system, with graft tipping the scales or speeding the outcome. Large disputes involving substantial wealth transfer will be something else entirely. These disputes will be resolved through the ability of one party or the other to apply the threat of (or actual) violence to the negotiation process.
These pressures won't only be the result of counterparties that have access or control the large mafias/gangs/militias (or corporate militaries) that will spring up during economic collapse (far larger than we've seen the US to date). Threats will also be mounted by government/defense/security officials that use their government sanctioned command of violence (police, SWAT, military units, etc.) as a means to personal enrichement.
This has pretty intersting implications for those GG readers that have large amounts of wealth in the current system. You might not be able to retain it or move it or transact with it in a collapse scenario w/o putting your life (and those around you) at mortal risk.
NOTE: We've already seen a taste of what's to come with the financial crisis of 2008. In sum: it was the biggest financial crisis to date, full of fraud and deception across the board, and almost nobody was punished for it. In fact, most were rewarded for their malfeasence with generous government bailouts and huge bonuses.