The whole Guergis scandal is a bit fuzzy this far on but, as I recall, she was unceremoniously dumped from the Tory caucus against her will, on the mere suspicion of scandal, and once out was kept out even after it was obvious there was no wrongdoing on her part save for her choice of a spouse. She was exiled, right from the git go and for good.
The only thing surprising about what happened to Dean Del Mastro was how long it took for him to be charged and why he was allowed to stay on in the meantime. The case was clear and it even came with a smoking gun - Del Mastro's own cheque.
Makes you wonder, doesn't it? Why did Harper not give Del Mastro 'The Full Guergis' treatment back when this scandal broke? Why did he keep Del Mastro in a position of prominence in the Tory caucus when that cheque speaks for itself and speaks so loudly?