You're correct, it's not an easy decision. You'd have to look at all the surrounding circumstances.
Obviously, right off the top, if it's under ministerial letterhead, then you conclude she must be acting as a minister. In this case, it was on MP letterhead. Then you ask, did it have something to do with her portfolio? You look at the portfolio of the minister, and if it was energy, mines and resources or something, you'd question, “Does that matter have something to do with EM&R?” There are probably four or five other questions you'd ask. You wouldn't need to ask questions sometimes because you would look at the circumstances and figure it out.
Look at the converse. Imagine if every time a member who was a minister did something as a member, and members are allowed under the.... It's expressly written out that a minister can act and do things that a member would normally do for their constituents. There's a whole plethora of activities that MPs do all the time for their constituents. I would have to ask myself, is there something being done over and above what is the normal course of an MP's job that suggests that their role as a minister has been implicated? I look at that, and, again, you can't decide that overnight. You have to ask around, ask the person involved, think about it, and understand the circumstances.