Do not worry. Just blame the developer because you obviously didn’t make a mistake. Ignore all the evidence, the database backups, the time stamped changes, just blame the developer.
An email has gone missing, don’t worry just blame the developer. After all it can’t be your fault, oh no that would never be the case. It must be the fault of the developer.
Don’t worry about not answering requests for help and assistance because it isn’t your fault, after all it won’t affect you. Ignore this chance to help the lowly developer. The developer is the enemy, you don’t need to be polite to them. Be nasty, be rude, ignore emails. Blame the developer.
When all goes wrong don’t even think of blaming yourself, just blame the developer.