Violations of campaign laws absolutely happened, by all parties, just as they happen every election. That doesn't address the point, though. The point is -- where is the evidence that the outcome of the election was rigged?
I don't think anyone's claiming that the results were fully determined ahead of time, just that illicit methods were used to nudge them by a few crucial percentage points. I'm not claiming it happened, but it's plausible - certainly laws were violated, and presumably those violating those laws did so because they thought it would advantage their party/candidate.