401k contribution reduced and never raised

[ratherbereading]

I have a plan who uses their accountant to do all payroll functions, including the 401k deposits. In 2014, he reduced a participant's deferral amount so he wouldn't go over the limit. In 2015, he forgot to raise it. In 2016, the participant noticed that he had only deferred $2,400 in 2015 instead of $18,000. The participant never checked his paystub, his investment house statements, or his bank account. Is this a situation where the participant is owed a QNEC? The argument could be made it was on him to notice that the deferrals were never raised.The accountant never notified the participant he was going to do this in the first place. It also affected his Safe Harbor match amount, of course.

Thanks in advance!

[WCC]

The argument could be made it was on him to notice that the deferrals were never raised.

Below is a quote from an IRS phone forum from September 7, 2012. My thought is you now have to follow Rev Proc 2015-28 to correct a failure to implement a deferral election.

Note: A Plan Sponsor cannot avoid liability to make corrective contributions for the missed deferral opportunity by making its employees responsible for checking pay records to ensure deferral election has been implemented.