"You have no idea what you're talking about" is not a good way to talk to someone. Its just more embarrassing when you get a counterpoint. I suggest against it in the future.

"If your code is being downloaded, such as HTML or Javascript or CSS, it makes a difference because the file is larger if spaces are used. How much larger depends on the number of lines and indent levels. It's the same as including comments in the code: they do increase file size.

If your code will be compiled, such as Actionscript or Java or C, or tokenized such as Perl, it makes no difference whether you use spaces or tabs, and you can include as many paragraphs of comments/documentation as you like, because it's only for your own benefit. All those tabs and spaces and comments will be ignored when the final, lower-level code is built."

https://stackoverflow.com/questions/7728829/what-is-the-difference-between-using-tab-and-space-when-we-do-source-code-format