A sell test is a state-bound observation.
How to read a successful transaction without turning one local result into a guarantee.
Start with the committed outcome
Read the receipt, the route, the actor and the output asset together. An eth_call result, a quote and a committed local receipt answer different questions. A successful root receipt also does not mean every internal frame succeeded.
Compare matching units
Token debit and credit getters describe reported balance changes. A difference can motivate an investigation, but does not establish a causal tax. Gas expenditure, pool fees, slippage and token deductions have different denominators. Do not combine native proceeds with token units.
Preserve the experiment boundary
The archived Ethereum case uses an isolated local fork. The buy, transfer and sell occur in a recorded sequence with their own receipt states. It does not reproduce every actor, transaction size, pool, block or future administrative change. The report retains these limits next to the outcome.