They rejected her return because I kicked two of the numbers on the EIN of one of her employers. The rejection was quick too, as we got the email about 20 minutes after submitting the return.
I always knew that the IRS checked your return, but I always figured it was something that eventually happened. I didn't think they checked everything as you submitted it. I don't know why I though that. Guess I pictured the IRS computer as an old IBM S/360 with core memory that did everything in batches.
I think that idea is common. But why wouldn't they automate it with modern(ish) hardware? It saves them money to do that. Just like it saves H&R block by creating a program. In fact I'm more surprised that H&R didn't flag it before you hit submit.