As usual, over-reaction.
Clearly the accounting error was not made by Wave. They plan to correct it.
Liability for the error is likely to fall on one of: the transaction's insurer (if there was one); the team performing the due diligence (an accounting firm); the previous owners.
Probably just a timing issue?
Presumably it is a material number or they would not have delayed the report.
Too early to leap to conclusions.