Late Challenge? Why Umpires Reviewed HR Long After

After a 7th inning Clemson double vs Miami, the offensive head coach didn't ask umpires to review the play until at least 60 seconds after it concluded, which far exceeds the maximum post-play time limit for challenges. Why then did umpires review and overturn the call to a home run?

NCAA and OBR alike specify in replay rules that teams seeking to challenge an umpire's call must first indicate they are considering challenging within 10 seconds of the contested play's conclusion and then must signal a challenge request within a certain amount of time after that (15 seconds after the hold signal in professional baseball / 30 seconds after the play itself in college).

Clemson's coach waited until well past 30 seconds to put his hands to his ears (the challenge signal), so why did umpires review the play?

The answer is that in both NCAA and OBR, home run boundary issues, including spectator interference on a fair fly ball at the outfield wall, are not subject to team challenge, but to Crew Chief or umpire-initiated review.

In turn, the head coach time limit does not apply to HR/boundary reviews and the umpires had until the next play (eg first pitch to the next batter) to invoke a review, which is what they did.

Video as follows:

Alternate Link: Umpires go to review well after play, but it wasn't a challenge