Those darned clients! But QBOA (QuickBooks Online Accountant) to the rescue. But you must be running the QBOA version of the program. There is a briefcase of tools available just to us for helping us best serve our clients. One of those options is an audit log of Voided/Deleted Transactions.
Yup, we know.....
When logged into the clients QBO database through your QBOA account, click on the briefcase next to the client's name. It will open up a menu of options for you, one of which is Voided/Deleted Transactions.