For checking the transcript: https://www.buzzsprout.com/2379282
Steal someone's thunder
means to take attention or credit away from someone, often at a moment when they should be the center of attention.

Examples:
1- Sarah worked hard on the team project, but her boss stole her thunder by presenting it as if it was his idea.
2- Jane was upset when her cousin announced her pregnancy at Jane’s wedding reception—it completely stole her thunder!