Minor Sion warding bug (or would it be a glitch?)

I've only seen this happen when the Sion is on my team, but when the Sion wards, I can hear Sion saying the warding lines, like "Let them sneak, let them die." and "A trap for vermin." This only seems to happen when the Sion is on my team, and only when he wards. It's not really that big of an issue, but it's still something that happens, so do what you will with this info. Maybe because his ult is heard by everyone, I don't know. Again, when my ally Sion places a ward I can hear him saying the ward placing line.