Going here:
http://m.mlb.com/video/topic/73955164/v36879667/ws2014-gm7-panik-dives-starts-slick-double-play

I took the numbers generated by Statcast to figure out what Hosmers time to first was.

The components are
1. Ball hit by Hosmer to Panic
2. Panic catches, relays to Crawford
3. Crawford catches and relays to first.
4. Ball travels the 90 feet to Belt

Assumption: times in video are correct, as below.
Calculated time of throw to first using:
Crawford to first is 86 feet (4’ stretch), at 105.9fps (77.2mph)

1.35 seconds Hosmer to Panic
.83 seconds Panic to Crawford
.77 seconds Crawford to Throw
.81 seconds Crawford throw to Belts glove

Times add up to 3.76 seconds to first.
Hosmer is left handed and fast. That seems like a slow time to first.

Did he get a slow jump out of the box? I don’t see any replays on his burst up the line.

I would guess the dive cost Hosmer .1 seconds at most. (too lazy to do the calculus of 18.1MPH -> 15.3MPH over an 8 foot distance)

The answer is that Hosmer didn’t take a direct route to first base. He started to take an arcing route in foul ground, thinking he had a hit and would round the bag. When he saw that Panik had made the stop, Hosmer adjusted and returned to the direct route up the line. But the false steps cost him. On the video, you can see it at about 3:03-3:08 if you look closely.