This is really interesting. The case pointed out in Ex.3 is pretty hilarious: (from the bash manual) The ERR trap [same rules as set -e] is not

This is really interesting. The case pointed out in Ex.3 is pretty hilarious: (from the bash manual) The ERR trap [same rules as set -e] is not executed if the failed command is part of the command list immediately following a while or until keyword, part of the test in an if statement, part of a command executed in a && or || list except the command following the final && or || [...]