I cannot tell from the tooltip, because Larian's tooltips and combat log don't actually give sufficient information, but what was the damage die that was rolled for the throw?
If there was no actual damage die - as in, it was simply a flat base, plus your strength mod, plus your rage bonus, then there is nothing *to* double, because crits only double your damage dice, not your modifiers.
If, however, it was rolling, say for example, a d6 for the object, which you rolled a 1 for, and it's just not telling you that, then yes, that d6 should definitely either get doubled or be rolled twice, for a crit.
