2010 X5 won't start

[TrojanBMW714]

Recently my 2010 X5 would not start. The starter was making it normal sound but it would not turn over. The sound kept on going on. After a few seconds I had to let go of the brake; didn't want to damage anything. Tow truck came and when we put the car in neutral (using the orange tool and manually removed car out of park). The car came out of gear and moved couple of inches. I tried starting the car and it worked. No tow needed.

I took the car the Shelly BMW, and they told me my battery is bad and gave me a new one. I don't think the battery was the problem. It seems mechanical and not a power/battery issue.

Any thoughts?