Slinkysista - I feel for you. I suspect though, that actually what this Consultant is saying isn't the big problem here.
By all means, tell her that you'd prefer that she didn't say it. By all means, expect that she will stop.
The BIG problem here is that the Consultant in charge of your DF's care is persuing a course of treatment that you think is inadequate. Crucially, you think that there are other courses of treatment that should be considered.
There are many times when patients and their relatives are naive and think that a Doctor's job is to fix the patient. The impression, often, given by media outlets, especially such as Casualty and Holby City, is that sick patient + determined and maverick doctor = well patient. It can be really hard to convey difficult messages gently. Relatives hear 'serious' and think 'it'll be ok'. They hear 'very sick' and think 'well he's in the right place!'. It's a natural defence mechanism, which is actually quite essential to coping with life.
Having said that, if you have read around the condition in question, have conversed with other medics who would potentially try something different, then you have every right to ask for a referral to another consultant, or ask PALS to mediate.
You only have your Dad once. If his condition deteriorates at any time, you will need to know that you did everything you could.
Do be aware though, that medicine really isn't as advanced as we may like to think in areas. Even with the most advanced treatments, there can be a very fine balance between the 'cost' of the treatment (and I mean to the patient, in terms of suffering, not the NHS in case of £) and the 'benefit'. It is a big decision, for example, when a Cancer patient has the choice of palliative care with weeks to live, or chemotherapy for a possible extention to months. Patients have to balance whether they'd rather have good pain management and a clear head for the remaining weeks, or the huge side effects of the Chemo to try and buy a few months. Not a decision to be taken lightly.
Please do talk to PALS, in any event. You are going through enough, without feeling that your DF's doctor isn't doing everything possible. Even if you come to an understanding with the doctor that her manner belied her desire to help your DF, you'll feel better.