Gads, my mom and dad had a doctor who was also arrested for Medicare fraud...this was some time after my dad had died, and my mom was living with me so I could care for her...but my aunt sent me an article about this doctor, and it did not surprise me at all...
I actually had to kick this doc off my dads case, as he was too weird for me...when my dad was dying of cancer, this doc, who was only my dads GP, wanted me to force my dad to have a feeding tube inserted, as my dad was not eating well...now, my mom and dad had let me know, long before they were ever ill, that they wanted no machines, no tubes, and just have palliative care, if they were terminal...my dads cancer had progressed to the point where he could not be cured, and even really treated, so his care at that point was more pain relief than anything else...but this GP wanted me to force my dad to have the feeding tube inserted...when I refused, he got huffy...and I sent him out the door, and on his way...thankfully my dads oncologist, who was the primary doctor on the case, was a fine man, and was livid at the GP for trying to insinuate himself into my dads case, and trying to force my dad to having something against his will...
Now that GP was a 'bad' doctor in the sense, that he tried to push his will onto people...he wanted my dad force fed, or he wanted to assault him with unwanted surgery...he did not know how forceful I could be, and that I believed that my parents had the final say, not the doc...
So it gave me a great deal of pleasure to see this guy arrested for Medicare Fraud...Karma, as far as I was concerned...
An IV to maintain hydration can sometimes be very useful pallative care if someone has difficulty taking fluid orally and is not so far gone that they no longer need water.
On the other hand, I see no reason why a doctor should feel a need to be excessively proactive with such things. If a patient complains of dehydration, give water. But if a patient doesn't seem to be suffering from dehydration, don't force it. While I wouldn't accuse the doctor in your case of putting other people's interests before the patient's, it would seem like he needs to recognize that forcing people to do something they don't want can cause more discomfort than would their failure to do such action.