This is fairly common in M&A and is called a "reverse termination or reverse breakup fee". In addition to the direct cost of having a deal fall through, you can imagine other damages from having a major competitor scrutinize your books.

Some notable reverse break up fees include: * a 6 Billion dollar fee AT&T incurred for failing to complete a purchase of T-mobile. * A 10 Billion fee (avoided) if Verizon backed out of buying Vodafone's stake in Verizon.