Absolutely. Homes with straight nailed studs can still get EXP. And that's why the Vilonia home should have gotten an EF5 rating.
Some of the EF5 homes in Moore only had 25% of their baseplates removed, and there's no "bolts have to be bent" EF5 requirement as far as I know. Saying otherwise seems pedantic to me.
Yes, the Wicker St home had its interior walls bolted down as well. Proof:
sorry if this explanation is a bit wordy, i tried my best to phrase it in a way thats somewhat understandable lol. tldr is if a home has bent bolts, it had a complete load path and is EF5. if it didnt, its EF4 (like vilonia).
to get an EF5 rating, a home needs to have a complete load path that can verify EF5 winds. straight nails often (but not always) stop a complete load path from occurring, such as in the case of vilonia. bent bolts are evidence of a complete load path, if there is no bent bolts, that means the failure occurred at the straight nailing rather than at the bolts, and no EF5 rating can be awarded. this is why a lot of EF5 homes often have toenailing rather than straight nailing, as toenailing better allows for the load the be transferred all the way down to the anchor bolts
its not the straight nailing that matters for an EF5 rating, but whether there is a complete load path. in the case of vilonia, the straight nailing prevented a complete load path from occurring, meaning there was no bent bolts, and therefor, no EF5 rating could be given. in other tornadoes, including (i assume) joplin, the straight nailing didnt stop a complete load path from occurring, and the force was still properly transferred all the way down to the bolts, bending them, even though the wall studs were straight nailed.
tornadoes can be straight nailed and rated EF5, or they can be straight nailed and rated EF4. its all about whether a complete load path occurs, its just less likely for that to happen in straight nailed homes
in terms of bolts being bent being a requirement for EF5, this is a quote from a paper on Moore 2013:
"it was decided that an EF5 rating would be assigned to homes that had the following characteristics:
1) foundation swept clean with debris strewn some distance downwind;
(vilonia had this)
2) foundation (generally slab) to base-plate connections with properly spaced bolts with properly sized, fitted, and tightened washers and nuts;
(vilonia mostly had this)
3) removal of a large percentage of the base plates from the foundation;
(vilonia didnt have this)
4) some anchor bolts bent (vilonia didnt have this)"
in regards to the wicker st home's interior walls, im 90% sure those are cut nails and not bolts, but i could be wrong. kinda hard to tell from the image but i think i remember reading in a paper somewhere that they were cutnails