What should the 2 leaders have done, to better affect the coalition?
How about this:
1) Perhaps talk about defeating the government publicly, but DON'T talk about a coalition.
2) Let Harper create the conditions for his defeat - pig-headed singularity, no compromise, while our leaders, day after day, express public concerns about the Harper policy line.
3) KEY POINT - Let the DAY of the vote come. Don't have some idiotic press conference days before a vote, allowing Harper a week of "wiggle room". You can do the press conference 1/2hr before the vote (or not at all). YOU CAN send the GG a letter expressing your "readiness", and the existence of an agreement.
4) Defeat the government. THEN show opposition solidarity, and show a coalition "newly formed" which was ready to take on governing.
The fact that it never happened this way may mean a couple of things. The NDP never really intended to see this through. They simply took advantage of Dion's lack of political savvy. They simply wanted to hold Harper's feet to the fire... Secondly, either Dion knew this, and let it go too far, or he was completely unaware and wandered into a trap...
Either way, it may all be water under the bridge now.