The article, if one bothers to read it, says that he was in the habit of taking late night walks to tire himself out. It doesn’t say he was institutionalized, or anywhere close to that.
It also says the Police had been out there multiple times. The family's version of these calls sound innocent enough, but it is THEIR side.
Alzheimer's patients can become agitated and even violent. A relative of mine took to bitting and scratching family members who were tending to her. I can see that being a more likely reason for the repeated calls then the ones listed by the family. Also, letting this man wander around when it's possible these spells could strike is all kinds of stupid, especially at night.