[No information useful to the Trump campaign was provided by the Russian lawyer. This fact means nothing.]

It is, as ACfH commented, easy for the parties involved to lie. However, it doesn't even need to be provided to the Trump campaign. The information could have been alluded to or even a brief overview of what the information was about (thousands of DNC emails) and Trump Jr. could have recognized how costly it would be to deal with the information in-house (not to mention how it would look if it later came out that they got the information from Russians) and said "Give it to wikileaks" which Trump had been supporting until he found out first hand about dealing with leaks.