Though it was apparently obvious in some cases, Luffy's fight with Magellan made me a bit skeptical.

* At the initial punch (Jet Pistol) Luffy touched the venomous body of Magellan, causing him extreme pain.
* In a later scene of the same fight, he used Jet Pistol to overcome his Hydra, but no sign of touching was shown.

In fact, in numerous cases, the way G2 works is ambiguous - some scenes imply that the pure speed even without touch creates an air pressure "sphere" that nevertheless causes huge injury when hits the target. Examples were seen in case of Blueno and much later, Doflamingo.

On the other hand, when he defeated Lucci, it was clearly shown that he actually punches him, and in several other cases it's often visible.

Which one is right? Or is itt possible that Luffy combines both?