Maybe try to confirm that, not trying to be a smart alec, but literally,so I think that synaptics is alredy disabled
one time , my computer would not even turn on. My first thoughts,
were that something with switch,...I thought, "I think it is plugged in" (It was plugged in the last time I used it),... well to get a better look at the switch, I needed to move the computer out from the under the desk, and guess what ?
Even though I thought it was plugged in, some how it had gotten unplugged,
probably my helper , a parrot named Bryan was up to his tricks,... he hates it
when I am busy at the computer instead of playing with him,... but that is
another topic. The main point just "thinking" it is disabled, does not confirm
that it actually is completely disabled.
All though tapping is disabled, I don't know that that means synaptics
is COMPLETELY disabled.
https://wiki.debian.org/SynapticsTouchpad
(xserver-xorg-input-synaptics has tapping disabled by default for touchpads with one or more physical buttons; see /usr/share/doc/xserver-xorg-input-synaptics/NEWS.Debian.gz. For a list of available options, see synclient -l . Not all options are appropriate; for example, Elantech touchpads don't support pressure, and many other touchpads don't support multitouch.)