"Slither" is definitely a negative term. A human doesn't slither, unless it is up to something nefarious, sneaky, malign, or evil. The devil is seen as serpentine in the Christian religion, and historically known as 'slithering about' to do evil. The apple offered to Eve, as part of the 'fall from grace' of humanity, was offered by Satan in serpent form.
The English language evolved and formed over centuries, in parallel with Christianity as a religion. Hence, many such negative or positively charged words and phrases exist.
For example, 'awesome' is "good awe" and "awful" is "bad awe", but why is "some awe" good, and "being full of awe" bad?
Because there is the concept that one cannot withstand being in full presence of God. Having some "awe" of God withstandable, but all? Will destroy you. To be filled with awe, something immensely wonderful to have some of, is horrible.
Irregardless of the current state of Christianity, English is derived from its historical, cultural roots, and some words can be "associated with malice". And again, I've only ever heard 'slither' used in reference to a human being in a highly negative connotation.
NOTE: I fully agree, especially on an international forum which has non-native speakers, assume good intent. However, the initial reply was not angry, or hateful, at least not from inakarmacoma.
Anyhow.
My 2 cents, worthful or not.
(Edit for all sorts of weird errors, and added a bit of context)
"Slither" can reasonably be associated with snakes, for which allusions are aplenty. The choice of word demonstrates a deliberate creativity that invited 6 the reader to consider whether there's deliberate underlying intent in the creative choice.
The "to life" comment takes an opinioated stance on the essence of what it means to be a living being, a controversial and deeply divisive topic for centuries.
Did you intend to inspire these interpretations? I doubt it. But is it reasonable to conclude you might have? Absolutely
No blame warranted, either way. Communication is flakey. ::shrug::
As for your other points, I highly doubt such a simple comment intended to touch on the complexities of what it means to be alive - any interpretation otherwise seems to be reaching hard to find a complex technical fault compared to the alternative of interpreting with hospitality and arriving at the conclusion that it was a simple colloquialism intended to describe the situation.
Also, judging by your comment you seem to believe I'm the one who made the comment that was interpreted as unkind.
There are many meanings to the phrase "come back to life". For example, my car "coughs into life" when I start it, and "comes alive" when I floor it, though nobody would infer it is actually alive. If someone "steps lively" that doesn't mean they are otherwise dead. A "live wire" isn't expected to be living, and also a person can be called a "live wire" meaning they're very engaging.
To "come back to life" in this context appears to mean simply that the person becomes animated and responsive to his surroundings. It's a phrase that would never occur to me to be offended by.