Thank you for your post, and I apologize for the late reply.
"Write" needs to be referenced within the Finder's context, so wrapping it within a "tell finder" is correct, and therefore, it will compile.
Besides, if you copy the first set of code into the Applescript Editor, it doesn't compile.
I agree with your analysis completely. But I believe that this is due to some bug in Filemaker's implementation of AppleScript. Since "write" does not appear in Filemaker's dictionary, it shouldn't (I believe) have any effect on the meaning of that word, but should just pass it to the wider context like most (all?) other programs do. I suspect that there is something in FileMaker's applescript code that is confusing the AppleScript interpreter--it is expecting FileMaker to either implement "write" or not implement "write", and FileMaker is doing something half-way in between.
Sorry for the vagueness of this analysis—I used to understand the details of Applescript from a programmer's perspective, but I no longer remember it, and, in any event, I don't have the tools to analyze the situation better.