I've seen much easier misplays called hits, so let's just label that Casas play bad luck. It appears to me the SOX have had more bad luck than good luck so far this season. Maybe it will even out in the second half.
This is as good a time to post BOSOX standings in the AL based on fielding % based on position entering today's game:
1st base--Tied for 10th
2nd base--13th
3rd base--12th
SS---------15TH
Catcher--Tied for 6th
LF--------Tied for 11th
CF-------Tied for 1st
RF-------4TH