Yes, it happened quite often when i did my Title Hunt.
My character does indeed speak for me sometimes lmao.
Edit: these are some lines my character said:
Perfect Landing.
Life is Pain.
Geronimo.
I meant to do that.
Your best bet would be to ask people if they remember any more quotes or try asking /u/Darkhearted_raven or /u/Jagexorion if they know the lines :p
Definitely not an easter egg based on me struggling to find the right animations for the scene. Some of the previous animations were... substantially more broken... and it led to these little bits of dialogue. They're pretty rare to be fair.