IOS 8: iMessage forces to send (instead of SMS) even without internet connection?

I own an iPhone 5s running iOS 8.0.2 (the latest update).

I don't know if this is just my phone or if it's just me who's finding it annoying and inconvenient but before, in iOS 7, if I have a contact who is available for iMessage and if I turn off the Wi-Fi (or if I don't have an internet connection), the message I'm trying to send will automatically be an SMS (send button will turn from blue to green). Like, with Wi-Fi, my message will be sent as an iMessage but with no Wi-Fi, it will automatically send as a text message/SMS.

However, ever since updating to iOS 8, that is not the case. Even with my Wi-Fi off, the message would still force itself to send as an iMessage (send button will still be blue instead of turning green) and then later on notifying me that the message have failed to send (obviously due to the absence of internet connection) so I will have to manually send it as a text message.

This is annoying for me since what if I need to quickly reach a person (with iMessage) through SMS but I have no Wi-Fi? I will have to manually long-hold the message to send as text message.

Is anybody experience the same thing as me? Any fixes or solutions? Anything would be greatly appreciated, thank you very much!

I'm not sure if I perfectly understood your problem or if you already have the correct settings in the phone but I will try to tell you what I know so far.In the setting>messages >the "send as SMS" was default switched to grey… Off in OS 7… But in iOS 8 it's on default I think. This means that it doesn't automatic send like SMS if Internet is lost… So you maybe can force it but. If you change that setting to green it will send as SMS if Wi-Fi not available. I don't know if that helped you but good luck!