He could have fumbled without being hit. It could be an errant pitch or backwards pass or something else. I would also probably presume it was an INT in fall camp but all I actually know is that ARod said he had one turnover.
If he didn’t fumble, we could live with the INT rate. The problem is the overall turnover rate and the fumbles stick out like a sore thumb because the rate is so high.
There are, of course, other issues with the offense, many unrelated to Jake. I wasn’t trying to comprehensively address this with the OP. Just the TO rate and that it’s pretty consistent with his history.