Certainly the code-G Form 1099-R with $0 in box 2a indicates that the rollover was intended to be to the traditional account in the new employer's 401(k). However, that doesn't mean that the new employer properly deposited it into the traditional account. If the funds were properly deposited into the traditional account and subsequently moved to the designated Roth account by an In-plan Roth Rollover, the receiving plan will be issuing a Form 1099-R that will have in box 1 the amount moved, the taxable amount in box 2a (generally same as the amount in box 1) and code G in box 7 that needs to be reported along with the Form 1099-R from the old plan. Check with the new employer's plan to see if they handled the direct rollover correctly and will be issuing a form 1099-R for an In-plan Roth Rollover.
It's often the case that the old plan does not accurately specify the account that is to be receiving the direct rollover, so it's entirely possible for the receiving 401(k) plan to deposit the funds into the wrong account, possibly at the incorrect direction of the employee which makes the receiving plan believe that the funds came from a designated Roth account in the originating plan when they did not. Checks for a direct rollover are often just made out to the new plan FBO the employee without more explicitly identifying the receiving account (or at least the type of account that is to receive the rollover).
