He didn't lied about shit. OP was meant to run only 5 years. Shueisha and Oda realized they can milk kiddos and here we are.
One Piece is far from over with this terrible pace and storytelling. Sooner or later Oda will get Togashi health and it will only get worse.
"Here's why Oda didn't lie the first time he said One Piece would end in five years."
"Here's why Oda didn't lie the second time he said One Piece would end in five years."
................................................................................................................................................................................
"Here's why Oda didn't like the third time he said One Piece would end in five years."
Obviously the dude was always lying about wanting to finish it quickly, what was he supposed to say? "I plan on drawing this Manga for at least another decade."