I didn't think Lampard's was a red. Therefore I think the decision is fair enough in isolation. However, when you see Aliadiere pick up 4 games for what he did...you have to ask questions.
I think the reason they added the extra game for Aliadiere was because it was clear he had committed a red card offence, and Boro pretty much accepted it, yet still appealed against it. The reason they appealed can only have been to get a punishment for Mascherano (or if they couldn't then at least, in their eyes, level things out, and have Aliadiere's punishment revoked). This was incredibly naive on their part, as the referee had already seen the incident and (incredibly) decided Mascherano did nothing wrong. And The FA were never going to rescind Aliadiere's, under any circumstances, ever. So its probably their own naivety that's got them the extra game for Aliadiere.