Subway/Railroad cross-honoring question

According to , LIRR service to Brooklyn will remain suspended for Monday's AM rush, and are saying that they will cross honor tickets for trains to Brooklyn. I've always figured, in the case of the suspensions, when they would occasionally cross-honor MetroCards for LIRR service to Penn (or vice versa). But since the and both stop at the express island platform (both Bronx-bound and Brooklyn-bound), how will officials know if customers are going towards Atlantic Avenue (or uptown to the Bronx) with an LIRR ticket? Will an LIRR conductor be on every car checking tickets? How does that work???