G27ROBOTS may not contact or otherwise interfere with their opponents’ PYRAMID. Inconsequential contact will not be penalized.
I’m strategizing going under the opponent’s piramid to get to ours and around the Defender bots. If I don’t interfere with an opponent’s climb, can I? There are no rules prohibiting (yet) this action as long as you don’t interfere.
As long as you dont contact any bot while they are trying to climb then you will be fine.
Also note that any bot touching its own pyramid will be interpreted by refs as ‘trying to climb’ even if they really aren’t. And if you touch them, automatic 30 pts penalty for their climb. Plus they can still really climb and get 30 more.
So going under the opponents pyramid can be quite risky…
(The above is based on my memory of various Q&A answers which its too late right now to go look up to cite.)
I’m pretty sure they’d only get the single 30-points. The rule says each affected robot will be awarded points for a successful level 3 climb. And since you can’t climb the pyramid twice… So I think it’s just that they’ll score the robot as if it made a level 3 climb.
This has already been addressed in the Q&A, game question 141:
Q. Per G16 and G27 a robot is awarded points for a Level 3 climb if their climb is interfered with. If the disrupted robot attempts another climb after the incident, is it eligible for additional climb points?"
2013-01-13 by FRC0639
A. Yes.
I’m in favor of this ruling, and of the general sentiment surrounding it. Do not defend robots at their pyramid, you will hyper-, super-, ulti-lose.
Strategically, using their pyramid as a route seems risky in concept. Can you outrun the defender by going through the pyramid, when all they have to do is begin their climb attempt? It will be interesting to see how much referees will be told to look for intent in these situations.
Go ahead and do that, just make sure I’m not on your alliance 
I personally don’t think it’s worth the risk.
If no other robots on the opposing alliance can fit under the pyramid, then it’s pretty much a safe zone (unless they can reach you with an extension beyond their frame perimeter). Just make sure they don’t start waiting for you on the other side. There is always the risk of large penalties, and as Steve already pointed out, YES, they can still get additional climb points after penalties, so be very careful. Don’t rely on it being an option.