Well you have your choice of:
1) general knowledge of animals and wolverines.
Or
2) Direct text messages from the perp where they claimed it was not them.
That's fair... But then why not state out front that that's what you're basing your speculation on?
"Based on my being a sheep rancher for 15 years, and having had several 'run-ins' with feral animals attacking my flock, I can't see..."
Or even, "Based on my just having re-read a couple of Wikipedia articles about animal behavior and specifically about predatory animals and overkill, I'd say..."
Already sounds a lot more reasonable, doesn't it?
2) Direct text messages from the perp where they claimed it was not them.
What "perp" are you talking about? This is an article about researchers tagging a wolverine. Who is the "perp" here?
Regards,