@Ericka G. When you go through a residential mortgage lender - bank, broker, whatever, what you are typically trying to acquire is a Fannie, Freddie, FHA, VA, jumbo loan. Specifically for what you are talking about, your friend was probably trying to get a Fannie/Freddie loan for the condo. Fannie/Freddie posts guidelines on the make up of a condo building - how many units are investors, percentage owned by one entity, commercial space percentage, etc. If you violate one of those guidelines, the loan is considered non-warrantable - meaning Fannie/Freddie won't do the loan.
Buying an investment property in a building that has an investor concentration of higher than 30% of the units is a major no-no. For that you would need to go through a non-warrantable option. Typically these have high down payment requirements, higher rates, maybe points.
Lenders/banks are notoriously unorganized. My guess would be that they didnt get the condo questionnaire back from the management company/association until very late in the process. That is why they didn't find out until the very last minute. A solid mortgage lender would do everything they could to get that form back asap in order to review it and protect your interest in the property.