Perhaps it is the slightly different timing a percussionist adds to the band, certainly not the usual jazzy triplet feel. I think it fits the Brazilian mood of the piece. Might be something to simply get used to - when I started playing in jazz groups I sometimes go that kind of reaction, even from fellow musicians. The phrasing is different, and maybe that clashes in your ears. No offense intended.
The berimbau is indeed difficult to use in such a context, as you have only two notes a half or whole step apart to play, so it's a drone, basically, that will not fit every chord, inevitably.
So its Haddad (tapping my own shoulder ), and he plays a pandeiro, which is the Brazilian tambourine - really sounds like an Indian kanjira at times the way he handles it. Interesting disc - as cheap as Naxos Jazz CDs are, this will be purchased soon! Thanks for including!