no, it is not ridiculous for you to be completely undergeared (just getting gear this week) and to be crit that much.
you were likely facing someone wearing best in slot items, possibly with quite a bit of pve gear, sitting at about or over 40% crit.
who had most likely had SR up, and blown their cooldowns.
400 resilience rating is 4.87% off crit damage, not 10% (you must be using level 70 values).
http://www.wowwiki.com/Resilience