I believe a casual observer CAN pick up signs about a player's level of effort. And I don't see consistent signs of effort on TO's part.
For me personally, I'd feel more reassured that TO was giving full effort if I saw him just once, for example, congratulate a teammate who made a good play. I don't think I've seen this yet, expect for when TO might have congratulated TE after Edwards threw him a TD pass. But that doesn't count because he was involved in the play.
Granted, TO has always been a me-first guy and congratulating a teammate is of course not the same as effort, but it does indicate where a guy's head is at.