Alba, 34, had said she was "body-checked" by the bodyguards while they made their way through the crowd leaving the fashion show, reported E! Online.
The actress had, however, not blamed Jenner, 18, for the incident.
"It was by two of them," Alba had said on Andy Cohen's Bravo talk show "Watch What Happens Live" this week.
"I was like, 'Whoa! Whoa! What's happening?' I thought there was like a fire. 'What's going on?' But I guess someone was just leaving the building. So, yeah, I don't know. It was really shocking."
"Wow! Came home to the most beautiful flower tree I've ever (seen)!" Alba wrote on Instagram, alongside a picture of the arrangement. "Thank you @kyliejenner you are a sweetheart!! So thoughtful.