I'd have thought getting up on the alter and lying in this way would be a huge insult to Catholics
That's one of the reasons why when I attend religious ceremonies (e.g. as a mark of respect for family, friends etc.) I don't participate in the sacraments - because in doing so I would be engaging in what the Catholic Bishops might term a "sham" and thus making a mockery of something that is very important to people who are close to me. The other reason is that I would be acting contrary to my own deeply held (atheistic) beliefs.
In relation to the issue of "sham" religious practices I would actually agree with many of the Bishops' utterances on these since they are often merely pointing out acts of hypocrisy - e.g. in the context of non practicing/believing individuals using church wedding, baptism, communion, confirmation, funeral ceremonies to suit themselves, President McAleese as a Catholic taking Protestant communion in spite of the deep theological differences between the Sacraments of the Eucharist as practiced by each denomination etc.
Conversely I would not agree with them, for example, describing my marriage (in the registry office) as flawed or invalid (as they have done recently) or their purported non recognition of state sanctioned marriages which have not received their blessing. However I acknowledge their freedom to express such opinions while reserving my right to rebut them.
Ultimately it's up to people to do what they want and, ideally, what they feel is right. If some people want to engage in sham religious practices then that's their prerogative. Many people I know, including family, do this and I consider it their business and not mine other than when it impinges on me (e.g. slight rumblings of discontent at my state rather than church marriage, having to decline the invitation to act as godfather to my brother's child etc.). However, I personally have more respect for somebody who acts in accordance with their beliefs, regardless of what these were. Curiously enough I had many Catholics, a la carte as well as devout, criticise me and my beliefs and try to bring me around to their way of thinking whereas I am generally content to leave them to their own beliefs and certainly would not try to "convert" them to atheism.