It's very easy to push with full force with your calf—you do it every day when you walk. Your calves enable you to go up on your tiptoes, so it's "easy" to make them work hard. Your tibialis anterior raises your foot towards your shin, which isn't terribly difficult. As a result, you (like most people) don't ever exercise it that hard. The problem is that the neuro probably didn't see much recruitment initially, only because you weren't pushing hard enough. If you push harder, you recruit more fibers. The fact that you can do it means that the muscle is fine.
Your neuro might have also seen something a bit unusual in your TA. This is nothing to worry about. In my case, my neuro saw a complex repetitive discharge (CRD) on my right TA, and told me that it could be a sign of chronic (old) denervation or muscle damage, or it might just be an odd reading. She proceeded to sample a muscle higher up on the same nerve root, found nothing wrong, and decided that the single unusual reading was an anomaly. The same might well have happened to you. I used to get very painful shin splints; I can imagine that this might cause (or result from) minor damage in the tibialis anterior.
How did a sore TA make you walk funny? Was it the shin pain, or was it inability to ilft your foot towards your shin? Did you have foot drop in those two days? If it's just soreness, I wouldn't worry about it. Even if it's foot drop, it's unlikely to be serious if it went away.
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