Chalk that up to one of Sony's worst engineering choices. Somewhat amusingly, most people have the OPPOSITE problem as what you're having; their drive ejects the disc all the time rather than not at all.
The way it's SUPPOSED to work is, the metal tab on the left side is supposed to make contact with that copper plate when you press the button. That completes the circuit and ejects the disc. So, yes, that silver prong should be touching the copper plate but NOT at all times. Only when the disc is supposed to be ejected. Typically what happens is that metal bit deforms over time and makes constant contact, causing the disc to always eject. The commonly accepted fix for that is to put a bit of electrical tape over that copper plate and simply use the software eject function, but that doesn't help you. In your case you're probably right; you probably bent it a little bit. You can try bending it back but your tolerances are very small; too much and it will constantly eject.