Tom Bertram was right - everything WAS his fault (but not for the reason he thought).
Had Tom not racked up so much debt, Sir Thomas wouldn't have had to sell the Mansfield living after Dr. Norris died, meaning Dr. Grant never would have bought it, meaning the Grants never would have moved into the neighborhood, meaning the Crawfords never would have come to stay with them, meaning Maria, Julia, and Edmund never would have had their hearts broken, Fanny would never have had to deal with a proposal she never wanted and all the fallout from her rejection, and no affair between Maria and Henry.
So, yeah, Tom, even though Maria and Henry already slept together in Sotherton woods long before that stupid home theater scheme, this whole mess was indeed your fault. Wonder if Tom ever realized the role his debts played in so many of his family's problems...