How long have you had the phal? One reason for bud blast is the change in atmosphere the plant endures when brought from one location to a new one. Another is dryness, yet another something in the atmosphere. There could be a number of reasons that would cause the buds to blast. The hurtful part is that the buds blast just on the verge of opening, which fools you into thinking that the next morning you will see the start of a bloom.

I don't think the 65 degrees is the cause. However, do you have it located by a window and maybe it is getting colder than you think?

65 is not too cold, in fact to get your phal to rebloom it should experience night time lows around 60 degrees (in the appropriate fall and winter season). Phal's are one of the best to not experience bud blast when moving from one environment (store) to another (home). However, that does not mean it will not happen.

You did not say what your orchid was potted in (medium and pot style) nor how the roots are doing. The roots are critical to success of orchid growing - whenever you have a problem you should always check the roots as they tend to tell you if there is a problem way before you see it in the flowers and leaves.

I agree with Paul_Mc, I think the temp is fine. Check the roots. How much water are you giving it? How much light does it receive?

Sarah