Rules of a Travel

On Monday night there was a 'travel' call made by the opposition on one of the Heroes players throw which lead to a scoring catch being made. So as you can imagine that was kinda annoying, so here in the Heroes secret hideout we thought we'd check the rules to understand what constitutes a travel. Now the Defensive player (we won't name names, but they are very experienced and we certainly respect them. This is not to contradict their call but more establish what a travel means) ...called a travel because "the thrower dragged his pivot foot when releasing the disc". So what do the rules say?

18.2.6.4. the thrower fails to keep the established pivot until releasing the disc;
18.2.6.5. the thrower fails to maintain contact with the playing field throughout the
throwing motion;

So what happens when the offensive player, in this case the Heroes player, accidentally drags his pivot foot, along the ground, not pulling it off the ground, in the motion of throwing the disc. So I ask is this called correct? It may be, I dont have a problem with it, but the rules only state that their must be contact with the ground at all times. So because the Heroes player DID maintain contact with the playing field throughout the throwing motion is it a travel?

Secondly the wording of the first rule implies that you might be able to include a pivot drag in the act of releasing the disc. If the rule meant you couldn't drag your foot in the act of throwing it would read:
The thrower fails to keep the established pivot until the disc has been released. (ie left the hand)
BUT the word 'releasing' (means still leaving the hand) was used. Because the 'ing' constitutes motion. Motion is therefore throwing. If then in the act of throwing you drag your foot, it is not a travel - right?

Sure you cannot drag your pivot up the field to gain meters but actually if I am interpreting the wording correctly, in the act or releasing the disc, if there is a drag - its ok?