People legitimately disagree about value. Investment horizon is a large factor. Two teams can do the opposite side of a trade and both profit on different horizons. Usually the agreement or disagreement is statistical, executed by a program in small fractions of a second. There is almost always some noise involved at the exchange, sometimes even some intentional randomness. It's not the same as getting people talk to each other about a project.
"Deutsche has paid more than $9 billion in further fines and settlements related to claims of tax evasion; violating sanctions against Iran, Libya, Syria, Myanmar, and Sudan; rigging the $300 trillion Libor market'
None of these are a byproduct of programatic trading.