Put it this way: the guy is a decent enough climber to win a mountaintop finish in the Giro, and resilient enough and good enough in bad weather to top 10 Gent-Wevelgem in that horrible spring season a couple of years ago where half the races got abridged or cancelled.
And he was still unthreatening enough to be allowed into the smaller initial break in stage 4 without anybody minding. After all, it's not like he's come out of nowhere or anything, he's been around the bunch for five or six years now, we know his level... (edit for clarification of point: and it isn't GT podium)
Because of that early time gain and previous reasonable if un-spectacular results, and certainly if he falls away at least from the leaders if not from the chasing guys in week 3 it's perhaps more 2010 Tour Hesjedal than Búfalo, but atm his GC position is pretty eye-opening even in this field.