Pagano and Atlanta Falcons coach Dan Quinn were the only two head coaches in attendance, but a number of position coaches from several teams were on hand to watch the workouts. Draft Insider's Tony Pauline notes that Pagano was the one leading the defensive back drills.
As far as defensive backs go, safety Darian Thompson is the most intriguing name of the group, who is projected as a third round pick by CBS and has potential as a playmaking free safety. The Colts could use another developmental safety like Clayton Geathers last year, as Mike Adams is 35 years old heading into the 2016 season. Another defensive back who was working out at the Boise State pro day was cornerback Donte Deayon, who is a projected fifth or sixth round pick by CBS.
The biggest prospect at Boise State's pro day, though, was pass rusher Kamalei Correa. The Colts have shown interest in Correa, as they met with him at the NFL Combine, and considering the team's need at pass rusher they absolutely would be wise to look at him. He has the athleticism to play as a 3-4 outside linebacker and would address a huge position of need. CBS projects Correa as a third or fourth round pick, and he'd be as good of a pass rusher as you can find at that point.
It's likely that Chuck Pagano was on hand to watch both Correa and Thompson (plus perhaps others like Deayon as well), and both players could help the Colts at their respective positions.