Del Mar Derby: To DQ, or not to DQ?

I rarely concern myself with stewards' inquiries or objections following a race but I think the events of yesterday's Del Mar Derby (chart) warrant an additional look.  (If you didn't see the race you can watch a replay here.)

Twirling Candy clearly interferes with Summer Movie coming off the first turn onto the backstretch (if you watch the head-on replay it's even more obvious) and I think it's pretty clear that the interference caused Summer Movie to alter course and lose ground.  And even though Twirling Candy was easily the best horse in the field I'm not sure he should have stayed up given the Riding Rule of the California Horse Racing Board.

According to Rule #1699 (b) and (c) of the CHRB:

(b) A horse shall not interfere with or cause any other horse to lose stride, ground or position in a part of the race where the horse loses the opportunity to place where it might be reasonably expected to finish.

(c) A horse which interferes with another and thereby causes any other horse to lose stride, ground or position, when such other horse is not at fault and when such interference occurs in a part of the race where the horse interfered with loses the opportunity to place where it might, in the opinion of the Stewards, be reasonably expected to finish, may be disqualified and placed behind the horse so interfered with.

From the letter of law, as declared by the CHRB, it's questionable as to how the Stewards could have left Twirling Candy up as the winner since he clearly caused Summer Movie to lose ground.  I can only assume that the decision was predicated on the phrase "the horse interfered with loses the opportunity to place where it might, in the opinion of the Stewards, be reasonably expected to finish" and that the Stewards concluded that Summer Movie would have finished last regardless of the incident.  Considering that Summer Movie was second when the incident occurred and ultimately finished last I'm not sure how they could have come to that conclusion.

The Stewards' job is never easy but I'm not sure you could ask for a more clear example of interference.