The assumption doing the most work in both positions is whether "completed" attaches to the task or the outcome. The vendor argues four loads hauled is four loads delivered, a discrete, verifiable unit of work. The investor argues the contract is for a cleared property, and the abatement process now controls that outcome, so nothing is settled. Neither reading is wrong, which is exactly why the gap exists.
The standard fix is a force majeure or government action clause that does two things separately: defines which events trigger it, and specifies payment treatment when it fires. Most boilerplate collapses those into one vague sentence, so you still end up arguing about what "equitable adjustment" means. The clauses I have seen that actually hold up split the job into discrete, billable milestones with a dollar figure attached to each, and state explicitly that a government interruption entitles the vendor to payment for milestones completed before the stop date, with no further obligation on either side unless both parties agree in writing to resume. That framing converts the dispute from "was the contract performed" to "which line items cleared the milestone threshold," which is a factual question rather than an interpretive one.
The risk the post does not name is the abatement cost itself. If the city runs its own cleanup, it can lien the property for the recovery amount. That lien may attach ahead of other claims, and it can affect title. The investor assuming the abatement "wipes the slate" may be correct on the contract dispute but wrong on the financial exposure. Whether that lien is senior, how the recovery amount is calculated, and whether it survives a title transfer requires a real estate attorney in the relevant jurisdiction, not a contract clause.
On the vendor side, the practical protection is requiring a deposit equal to the first milestone before work starts, so the hauling runs are already partially covered regardless of what happens after.
What did the contract define as the unit of completion, a haul count, a cleared space, or a sign-off from the client?