Since you mentioned hurricane Sandy I would give the board member the benefit of the doubt. Sandy was an unusual disaster that wreaked havoc in downtown Manhattan and other areas. People were displaced and even NYC streamlined and attempted to expedite their usual long bureaucratic procedures to place homeless victims and re-build.
Having said that, there are apartments in some coops that the board owns. In HDFC coops in particular. Apartments that the board owns. They can sell the units but many coops lease them to generate income for the coop. These apartments are not sponsor or un-sold shares because all the shares were allocated when the city sold the building and the HDFC was incorporated.
As Nick said if it's "hearsay" check the facts to be certain there was any impropriety. Coops are private corporations with very little accountability and transparency.
Real estate brokers and salespersons are licensed by NY state. Brokers must take 75 hours of education courses exams and 22.5 hours of continuing education every two years. To become a Director of a coop board there is no education, training special skills or knowledge of law, real estate or fair housing required.
While the majority of coops in Manhattan are well run, managed and operate in the best interest of their shareholders there will always be some bad apples in NYC.
Lic.Assoc. RE Broker
The Corcoran Group
Licensed Associate RE Broker
The Corcoran Group
Lastly, I don't see how a board member could "take an apartment" in the first place. A resale can't be taken, only bought. If this person is the sponsor and it was a sponsor unit, you're out of gas as they can sell to whoever they want without any vote or approval. Best to check you facts, then talk to the other board members to see if you can get a consensus then go see an Attorney. Be ready for plenty of bad blood. Good luck.