Indeed the aircraft could suffer a significant deflection from its original track on collision with something that substantial.
30 degrees easily.
60 degrees possibly.
90 degrees? I suspect that it would disintegrate completely on collision rather than "bounce off" in that way.
Glad someone noted that direction of travel after the collision could be very different from the direction before.
At least one picture purports to show the tail of the helicopter separated on a building roof. If true, a helicopter that has lost its tail rotor will be spinning like a top, and can veer off in any direction.
It isn't really a "bounce" - it is a complete loss of directional control from what may have been a "moderate" collision (n.b. the thin tail boom and long thin tailrotor driveshaft are far more fragile than the cockpit area - helo tails have failed with no collision at all). If you do physically lose tail structure (weight), you go nose down as the c.g. shifts forward and the residual thrust in the main rotor can shove you off in whatever direction you happen to be pointed in the spin - even 180 degrees to your original heading.
The path of a helo with a failed or missing tail rotor effectively becomes a "random walk."
I hestitate to link to Youtube since the embedding is now automatic, and not everyone wants to see the video. But search "helicopter loses tail rotor" there to see the real dynamics of what can happen.