Yes, it's not uncommon at all for 10 meters to have worldwide propagation near the height of the sunspot cycle. It also doesn't take a lot of power or big antennas to work the world on 10 meters when the band is open. I remember sitting in my car one day back in the summer of 1998 and working Japan, Australia, Guam, Hawaii, and New Zealand all in the course of about an hour. I was using a Ranger 2950 that my brother let me borrow and a CB antenna on the trunk of my car. Running only 25 Watt with that setup, I had a blast!
73,
Michael KU4UV