How so? Have you no room for an honest mistake? DiLorenzo has indicated that perhaps the most major of these 4-5 complaints was an honest mistake, and took measures to correct it. I don't think it is reasonable to smear him over as a "liar" and "fraud" over that one error against him for a book of 300 pages.
A second of the oft-cited "errors," the 1857 thing, was a mistake made by somebody else that DiLorenzo transfered inadvertantly when he cited the earlier work as his source. That doesn't establish the charge "liar" against him either.
The rest of the complaints are almost all disputes over interpretations of quotes by other authors.
Further, I believe every one of these reasonably qualifies as "petty" and invite you to explain otherwise.
Please do not forget the part where DiLorenzo not only took a SECONDARY source as gospel (which ought to show you how bad his scholarship is), but ADDED in the "fact" that Lincoln was in the Illinois legislature.
That goes beyond a "mistake." That's technically known as "making stuff up."