[TexasFreeper2009]

You are correct, they were his guardians but apparently were not given medical power of attorney, thus the ruling was correct.

However IF they had been granted medical power of attorney by the state, then they could have denied the use of a ventilator to prolong or save his life, just the same as anyone else who doesn't want such measures used on them.

[wagglebee]

I am not aware of any laws that allow regular guardians to end a person’s life.