We've not really delved into the outward facing machinations of legislators, so I'll use Rep. Logey's words to hopefully shed some light on this:
When legislators broke for recess, what they were doing is deciding the final vote on bills for executive action. Knowing that there were 2 strong no votes from the majority already, there needed to be a decision made on who would be the last vote to table the bill. They selected Mitchell, mostly because he's disposable to them as it is after his big media attention grab on his Antifa resolution. He also, as a freshman, can claim other motivations, etc rather than simply say "this is a chitty bill and my folks back home really don't support it."
Votes are generally managed outcomes in committees. This bill, by virtue of who the sponsor is, and the agency's request that it pass, had to be handled a bit more delicately in order to save face when it dies. That saving of face also comes with the condition that some legislators will respond to post-vote inquiries with a standard response, such as Rep. Logey's admonition that hunters aren't bringing solutions (which is what others have said - it's a repeated refrain on anyone who opposes a bad bill).
What we saw last night in committee was largely theater. Legislators will deny this, but the reality is they decided who was going to vote no or yes in the GOP caucus. Th Dem caucus was clearly against the bill, so only three people needed to vote no. With the two from the Flathead already there, it made sense to give the last no vote to Mitchell as opposed Logey (Chairman of another committee) or others who would be in leadership.