What do you think about the word 'retard'?

I am in a bit of bother with our "equality and diversity specialist" because after months of dealing with her teams ineptitude, I went into her office and - assertively not angrily - asked if she only employed retards.

To be clear, non of her team have any kind of (visible) handicaps. But they are not all they could be. Often I hear them talking about the stuff they like and it's obvious to me that they are mentally docile and lack and sense if cultural curiosity. Often they are talking about cooking and food. Therefore I believe the word retard was OK to use in relation to them and and surveys, appraisals or diagnostics they hand into my team always mean we got to do a shit load of leg work.

For me when I use this word, it simply means a human being (non handicapped) is not all they can be/could have been which concurs with the dictionary definition.

I think she's been opportunistic hear because she's fat and a lot of the 'retards' I referred to are fat also.