By issuing the LOI, DPDW has already indicated that they "want" Mako, assuming a thorough look at the financials does not turn up any negative surprises.
All that is happening right now is the "open up the kimono" check to make sure everything is as advertised. The deal would only fall through if DPDW were to discover some kind of skeleton in Mako's closet, which to me seems very unlikely.
Think about it--it actually should be reassuring that DPDW intends to run all the traps and not skimp on their DD before completing the acquisition. Given the bio and rep of DPDW's CFO and CEO, I doubt they would be bamboozled, but it is still nice to see them do it by the book.
Relax--this type of DD period for the acquirer is absolutely standard procedure.