I'm thinking if they didn't use their last timeout, broncos would've had 15 seconds to get the field goal unit out.
That means they sub, so with like 7 seconds left the bills could've sent someone for their own substitution, and they should've been able to burn 7 seconds sending someone off and bringing someone back on, and the refs would have to hold the ball, and time would run out.
Just googled the rule i'm thinking of:
"If a substitution is made by the offense, the offense shall not be permitted to snap the ball until the defense has been permitted to respond with its substitutions. While in the process of a substitution (or simulated substitution), the offense is prohibited from rushing quickly to the line of scrimmage and snapping the ball in an obvious attempt to cause a defensive foul (i.e., too many men on the field). If the offense makes a late substitution, the following occurs:
- a) The Umpire will stand over the ball until the Referee deems that the defense has had a reasonable time to complete its substitutions.
- b) If a play takes place and a defensive foul for too many players on the field results, no penalties will be enforced, except for personal fouls and unsportsmanlike conduct, and the down will be replayed. At this time, the Referee will notify the head coach that any further use of this tactic will result in a penalty for unsportsmanlike conduct.
- Note: The quick-snap rule does not apply after the two-minute warning of either half, or if there is not a substitution by the offense.
- c) On a fourth-down punting situation, the Referee and the Umpire will not allow a quick snap that prevents the defense from having a reasonable time to complete its substitutions. This applies throughout the entire game.
- d) If the play clock expires before the defense has completed its substitution, it is delay of game by the offense."