Maybe not career ending, but definitely would be a set back. I wouldn't want to explain why I got disciplined for knowingly disregarding my work obligations at an interview, if you even get an interview with that on your app.

I spent 3+ years on reserve at my first regional, so I feel for the guy, but I wouldn't risk it.

The industry is in a hiring spree right now, don't lessen your chances of getting a call or getting hired.