iv looked into this issue a while back and i found it extremly hard ot reproduce becase of the fast energy regeneration.
however this tooltip is there since i think 4.1 in the mainwhile we had several patches in witch tooltips where fixed but this tooltip was never chanced witch makes me believe it realy does use up 35 extra energy.
the truth is if it does use up 35 extra energy the DPE of the attack goes down down when you burn extra energy on it