scheduling time mix up

Hello,

Trying to solve a mystery. We had an invite sent to us through Outlook that appeared on our calendar for 10am.  The organizer set it for 9am and showed us a screen shot of the meeting on her calendar as 9am.  How might have that happened.  I can't tell from the calendar item if the time zones were set incorrectly on the organizers end. Might that be a possibility?

thank you!