I really don't think it would be all that difficult to come up with a rule that prohibited simply giving another team an answer without precluding the possibility of teams working together. How about something like the following?:"Teams may work together to complete roadblock tasks, but they may not simply pass on the correct answer to other teams once they have completed the task. If they do so, they will be assessed a fifteen minute penalty for each team they illegally assist."
Really, if they think it's too much trouble to differentiate between teams working together and teams passing on the answers to others, then I'd prefer they make it illegal to work together on tasks as well. I want to see all the teams work through the task. I don't want it to come down to one or two teams completing it correctly and then deciding who to help and who to screw, as happened last season with the Cowboys.
It also bugs me that it appears to be against the rules for a team to help another team with a physical task but not with a mental task. Either they shouldn't be able to help with either or they should be able to help with both. About the only time I can remember anyone helping another team with a physical task was when the coal miner guy helped an all female team with a heavily loaded cart in that coal mine. Mostly, help is only given with mental tasks, which gives teams that don't do as well with such tasks but attach themselves to teams that do a distinct advantage that they don't seem to be returning when it comes to the physical tasks at which they might excel.