Hunter's Run discussion

This book really confuses me when it comes to the language of the main character and use of units. The writers make it very clear that Ramon is from Mexico and that the aliens speaks Spanish to him. So why on Earth is the book written like he speaks English with lots of Spanish words thrown in? Makes no sense at all. Also, as a Mexican he wouldn't use feet and pounds and other Imperial units, he'd use the metric system.

Lazy and/or ignorant writers I guess.