What do you mean "not obviously, but in way that you can tell they did it on purpose"? If they did it where it is obvious they did it on purpose, it's inting. If it's not clear they did it on purpose, it's not. You don't get to say that you're some magic omniscient being who "can tell" - it's either clear to an unbiased third party (i.e. a Riot employee/support agent) or it's not. You are not somehow better at this than an unbiased third party - and in fact, by being in the game, you're the last person who should be "trusted" to determine inting.
Someone not going for objectives does not make them a troll. Having poor jungle pathing does not make them a troll. If they're dead, on the top side of the map, it isn't warded, etc. and the enemy jungler happens to get it first, that's not trolling, that's losing in skill as a team. The jungler is not the only person with responsibility for dragon/rift herald. If you are bot lane, you should be ensuring vision of not the pit but the paths to the pit. If the enemy jungler starts to try and solo dragon, you go make them stop it. If the enemy team starts to fight dragon (i.e. including mid and/or bot lanes), then that's a failure of your lanes to provide pressure. None of that is the jungler's fault.
Split pushing against a team that is heavily dominating is the right call 99% of the time. When it becomes clear that 5v5 fights don't end in your favor, why would they keep doing them? You know the saying "he who repeats his actions expecting a different result is a....."? Well it applies here. Your jungler saw that you weren't winning 5v5s and weren't making any progress by grouping all 5 together - so they tried something different. You'd rather them just sit with you and let the enemy keep chipping away at your towers until they win?
