Proper way of typesetting dot over indexed variable

What is the proper way to put a dot over an indexed variable, like for Netwon’s derivative notation? For typesetting reasons, I prefer dot{x}_i, but my colleage argues that it’s an operator on x_i and hence it must be dot{x_i}, which looks hideous if the index is longer, like dot{x_text{max}}. It becomes ever worse since I want to typeset vectors in boldface using the bm package, but then the dot is boldface as well, and that is certainly incorrect. Who has some wisdom for me?

documentclass{article}
usepackage{bm}
newcommand{vect}[1]{{bm {#1}}}
begin{document}

Is it $dot{x}_i$ or $dot{x_i}$? What about $dot{x_{max}}$? par
And what about $vect{dot{x}_i}$ or $vect{dot{x}}_i$, 
or maybe better $dot{vect{x}}_vect{i}$?

end{document}

Which yields this: