It is.
If you look at the odds for exact scores, and the spread, it is about 14.1 - 13.9.
I always think in events like this, nearly all betting is 'partisan'
When it is in the US, more bets are placed by US bettors and vice versa.
The odds are dictated by those bets.

Look at the PGA rankings. 4 of the 5 top places held by Europeans. Those are the only 4 that play the PGA tour. The others play selected ranking events only. Form book is in Europe's favor and that is equalised by your home advantage.
Over one round, especially in matchplay, any of those 24 players competing could beat any of the other 23.
Way too close to call if you were betting 'real' money on it in my opinion.