Absolute rate constants for rotational and rovibrational energy transfer in the system Ne-Li-2(A(1)Sigma(+)(u)) were measured by a dispersed fluorescence technique following excitation of the (v = Oj = 18) initial level of Li-2(A(1)Sigma(+)(u)). The rate coefficients for Delta v = 0 processes decline monotonically with increasing vertical bar Delta j vertical bar. The Delta v = 1 rate coefficients are also peaked near Delta j = 0 but show a broad shoulder extending to approximately Delta j = 30. Classical trajectory calculations and accurate quantum mechanical close-coupled calculations were used to compute theoretical rate constants from an ab initio potential surface. The agreement between the classical and quantum calculations is very good. The calculations slightly overestimate the measured rate constants for Delta v = 0, Delta j <= 6 processes but underestimate those for Delta v = 0, Delta j >= 20, implying that the anisotropy of the ab initio surface is too small at short range and too large at long range. For Delta v = 1 collisions, the calculations agree well with experiment for Delta j <= 0 and show the correct qualitative behavior for positive Delta j, including both the peaking at Delta j = 0 and the shoulder extending to positive Aj. However, they underestimate rate constants for Delta v = 1, Delta j > 0 collisions, disagreeing with experiment by a factor of 2 for Delta j similar to 20 but agreeing better at higher and lower Delta j. Analysis of classical trajectories indicates that the vibrationally inelastic collisions fall into two groups corresponding to equatorial and near-end impacts; the former generally produce small Delta j while the latter produce large Delta j. Studies of a simple model potential show that this dual mechanism may be a general phenomenon not limited to the particular potential surface employed here. Criteria controlling the relative importance of the two vibrational excitation routes are enumerated.