Push lock fittings are designed to be used without a clamp and for a 1/2" hose (-8AN) it should hold a pressure up to roughly 250psi without issue (varies greatly with manufacturer and quality/spec of hose also). HOWEVER that also means it was used with the proper hose and installed properly. As a general rule of thumb if you can push a push lock in by hand, you didn't do it right for high pressure applications, you have a mismatch is hose, or you have the wrong hose! They make push lock tools for installing push lock fittings. Essentially a hand held vice designed to insert these fittings. They STRETCH a braided hose when installing, which isn't easy to do. I see some slight "bumps" in your fitting that is still installed, but not what I would expect to see form this type of fitting. I'm not saying you cannot install them by hand. I've seen guys get one started and then put all their body weight into it, or grease them up in order to get them to slide in better, but I would not advise either of these techniques...
That said, I don't like to use push lock fittings at all, just my preference, but if/when requested the only time I would go clampless would be on a no pressure system (breather) or a low pressure system (carb fuel lines) and not a higher pressure system like oil or EFI. As mentioned above, a cheap clamp is simple insurance... or just uses wedged or thread in fittings and have peace of mind.