this can be true or they may be bluffing it. Even in ritz diesel in my case i do not see the light coming on, very few times i see it but that too for about 1/10th of a sec or so.
The manual says the light might glow for a long time in extreme cold conditions, which never happens in india,,may be in srinagar.Northern india belt ritz diesel owners may have something else to tell, lets wait for them to answer.