In many past games, simply touching a scored game piece made that piece not scored. The robot did not need to be supporting or grasping that piece, just contacting it, regardless of how insignificant the contact was.
How is this ruling any different?
So if you have a ramp bot, tubes are now your natural enemy (more so than before), avoid them at all costs. As it is so often said "It is just another part of the game challenge".
On a side note, are we going to see opposing tube bots chasing ramp bots around with a tube? It wouldn't be the first time
a game piece was used defensively on an opponent's robot. That certainly would add fuel to ramp bots vs. tube bots arguments. The great thing about this game strongly encourages the 2 strategies to work together (unlike shooters vs dumpers last year) so the arguments shouldn't get too heated.
EDIT: Kevin beat me to the "Tube Stalking" strategy
