You're right, there's no need to be snide about it.
The marine uniform on the whole isn't wrong, the one pictured just looked odd to me because I was expecting a private and got an officer carrying a longarm, which had me confused for a bit. Shouldn't have called it mishappen though.
The buttons and gorget are the wrong colour, they should be white metal, not brass, and the epaulettes should be white as well, but that's about the only accuracy issue I noticed. (The pattern and number of buttons is off as well, but I don't even consider that an issue... this is a game, not a recreation for a museum.)
The musket I'm merely curious about, I noticed the barrel bands which makes it something other than one of the various standard longarms of British troops in the 18th century, but couldn't tell exactly what it was.
Some sort of "brown bess" land pattern muske is fine for the marines, there's a sea pattern introduced in 1778 iirc, but I do not know in which quantities, if at all, that saw use in North America. Considering that new muskets weren't issued until the depots had been emptied of old ones, I'd guess there weren't many, if any.