Difference between pandas and hvplot for ecobee dataset

# Versions

| Package | Version|
|----------|--------|
| hvplot | 0.4.0 |
| holoviews | 1.12.5 |
| bokeh | 1.3.4 |
|notebook| 6.0.0|
|python | 3.7.3|
|Browser| Chrome 75, Safari 12.1.1|

#### Description of expected behavior and the observed behavior

The basic shape of the graph produced should be the same.

#### Complete, minimal, self-contained example code that reproduces the issue

Get CSV from here (250 KB): https://www.dropbox.com/s/m4cwi5kdve9x67n/report-319299697687-2019-08-07-to-2019-08-14.csv?dl=1

```
import pandas as pd
import hvplot.pandas

df = pd.read_csv("report-319299697687-2019-08-07-to-2019-08-14.csv",
comment="#")
col = "Thermostat Temperature (C)"
df[col].hvplot()
df[col].plot()
```

#### Screenshots or screencasts of the bug in action