Accompaniment Playing study 3 question

Hello David,I'm confused about the exercise in which we are to play the appropriate chord tones for each chord, I IV V of a blues progression that are available in each hole.  Holes 1 through 4 I get, and hole 6, but I don't see how it is possible to get a pitch for each chord of a blues progression out of hole 5.  The E is available as the blow note, so that covers the IV chord, but, while you can bend the 5 draw enough for expression, it doesn't bend to a true F# and, to my ear, the quarter tone bend sounds pretty rough against the V chord.  The 5 draw without bending gives you the flatted 7th tone in a I7 chord, so it works well against the 7th chords that strongly predominate in the blues genre, but I don't see where you're giving that explanation for its use in the videos.

Am I missing something fundamental? 

I saw in one video where you suggested not being too dogmatic about only playing the appropriate tones, that you could use an appropriate tone from an adjacent hole.  If so, will that be appropriate for the submitted test?