The plugin that translates the youtube URL to the embed is ignoring the "&t=" parameter. I've seen similar issues in some embeds using the shortlink version of the youtube URL versus the longer URL but a quick test here says that's not it.
The URL https://www.youtube.com/watch?v=If3SXJeZzMQ&t=27 translates to http://www.youtube.com/v/If3SXJeZzMQ&ap=%2526fmt%3D18&fs=1 and you can see the "27" part is stripped off.