Hi Simon! Thanks you for the explanation!
I have re-done the test, and it runs almost as you said. The request is also done in parallel on every server when the ttl is gone (before the 30 seconds). My ISP has set a 10 seconds ttl to their hosts... All queries are done with the same source port and dnsmasq seems to close the port as soon as the first server has replied, generating ICMP "destination unreachable" messages, is this the intended behavior? Here is the tcpdump attached, just in case!
naboo-dns-only.dump
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