I have played many games of Phoenix Wright so I am comfortable in asserting that the answer lies in the evidence. I call to the stand expert witnesses Wayne and Garth.
Wayne and Garth and their buds (seen here before Phil joins them on a No Honk Guarantee) rock out to Queen. During the film's initial theatrical run, Bohemian Rhapsody was re-released on the Wayne's World soundtrack. It hit #2 on the Billboard charts and became a fine tribute to Freddie Mercury, who had died a few months earlier.
The answer is all too clear.
Wayne plays the first five notes of Stairway to Heaven in a guitar shop, breaking store rules and annoying the employees. But that's only in the original theatrical cut. Zep wouldn't give up the rights to five lousy notes for the home video and TV versions. For all subsequent releases a random rock riff was dubbed over Wayne's playing, effectively rendering the joke null and void although the sign retains its meaning in a meta sort of way.