[sm0ke]

Actually man, they used a lot of invis pots and the reason you didn't see anyone recall is because in a situation like that, even if you try to invis recall, you're probably not gonna make it It's usually better to try to survive.
Here though, since you have 100 mana + (40?) from the potion. That's why people recall, because they don't want to get ganked 2v1 when they can't survive (because they have no mana).

True, I honestly would have no problem with invis pots if they took a certain portion of health or did something like the res penalty because with invis pots reflect and recall scrolls with trees losing it's another big reason as to why it's almost impossible to world PvP 1v1 or in several amounts of people 4v4 5v5 etc