Let me start by providing you with an example of what I'm considering:
You have been in poor health for a month or so. You've gone to your primary care doctor who was stumped by your illness. He sends you to a specialist for further testing. In the meantime you've been eating healthier, getting more rest than usual, been conscientious about the amount of water you consume because you know it will aid in flushing out any impurities in your system. You actively stay away from people you know who are ill, but you still are in poor health with an occasional "good" day. Nothing seems to be breaking the overall feeling of illness until one day the specialist's office you had an appointment with two weeks ago calls you to inform you that they have a diagnosis and you should come in right away. You schedule an appointment for the next day. Three days later you see your cowan best-friend who asks how you're doing. You relay the good news; that you're finally feeling better and that friend claims full responsibility for your current good health. It was all their doing, you're welcome.
From the mundane perspective this scenario would suggest that your muggle friend had some valuable medical knowledge and informed the physician of the underlying cause of your malady, right? Amazing! Is your friend Dr. Gregory House? It is rather a tad insane for your friend to claim responsibility for your returning health. Weren't you working on it yourself for months? You were doing the work and putting in the effort to return to your former state of well-being. What did your friend do? What was your friend doing all the previous months when you could have used their help? Did you even ask them? From my perspective it is rather presumptuous on your friend's part to claim responsibility for something you have been working on for months.
If we shift this example to a magickal perspective:
You have been in poor health for a month or so. You've done all that I've described in the above example, but have also done some magickal workings to improve your health. You've consumed healing teas, received Reiki and other healing modalities, and followed some of your Grandmother's "folk remedies", as well as done your own castings, but you still seem to have an underlying funk until one day the specialist's office you had an appointment with calls you. You schedule an appointment for the next day. Three days later on the Winter Solstice you meet up with some pagan friends to celebrate the holiday with, most of them you haven't seen since you started feeling ill. One Witch asks how you're feeling and you share with him that you are feeling much better; thank you for asking and his response to you is, "Glad you liked the Yule gift I gave you. "
The implication is that he cast a spell to make you better or removed the curse that made you ill, whatever or however he did it; he did it. Your current condition and over-all well-being had nothing to do with your work or effort or witchcraft. It is so absurd to me that I can't help but laugh. Even if I concede that others have influence over us, if we are aligned with our own power, our own magick, then another's Will is just an influence and not more powerful than our own Will. If we truly believe that we are the sovereign of our own power then another's cannot override our own unless we allow that it. Thinking that I am able to discount another's own intention or another's own spiritual journey is pure arrogance and ignorance. It is working with someone's Will and intention that is the key to influencing another to do as I desire or to think, feel, and believe as I want. Magick takes the path of least resistance so finding a way into that individual's psyche is what Witches do when they seek to manipulate another for good or bane. It takes less effort and work to coerce than attack; to work with consent and openness than to fight against another's Will or geas.
When another Witch claims responsibility for something you've been working on, such as your health, it attempts to remove the work and effort you've been expending on your own condition and focus on what he or she is capable of doing in order to show how "special" he or she is. The fellow Witch is in essence implying that you were inept at handling your own shit; that you couldn't get it done without them, but I don't believe that to be true. Claiming responsibility for another Witch's castings or workings is undermining that Witch's confidence in their own abilities. Why would anyone want to do that to someone else unless they themselves are feeling weak and insignificant. Putting someone else down in order to feel more powerful has been done throughout history. I completely understand that every Witch will not be friends with every other one, and I realize that we can't all "just get along", but I encourage you to evaluate why you do as you do; and question other's motives in the same way.